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Metallurgy of Cast Iron 


A COMPLETE 

EXPOSITION OF THE PROCESSES INVOLVED IN ITS 
TREATMENT, CHEMICALLY AND PHYSIC¬ 
ALLY, FROM THE BLAST FURNACE 
THROUGH THE FOUNDRY 
TO THE TESTING 
MACHINE. 

A Practical Compilation of Original Research. 

BY 

THOMAS D. WEST, 

»i 

PRACTICAL MOULDER AND FOUNDRY MANAGER; MEMBER OF AMERICAN 
SOCIETY OF MECHANICAL ENGINEERS, AMERICAN AND PITTSBURG 
FOUNDRYMEN'S ASSOCIATIONS, AND HONORARY MEMBER OF FOUN- 
DRYMEN’s ASSOCIATION OF PHILADELPHIA; AUTHOR OF “AMERICAN 
FOUNDRY PRACTICE,” “MOULDER’S TEXT-BOOK,” “INSTRUCTION 
PAPERS ON FOUNDING, FOR THE INTERNATIONAL CORRESPOND' 
ENCE SCHOOLS,” AND ORIGINATOR OF THE A. F. A. STANDARD¬ 
IZED DRILLINGS BUREAU. 


FULL Y ILL USTRA TED . 


Tenth Edition. 



CLEVELAND, OHIO, U. S. A.: 

THE CLEVELAND PRINTING AND PUBLISHING CO., PUBLISHERS. 

1906 







Copyright 1906. 

By Thomas D. West 



6 -j yp-rfi, 




FABLE OF CONTENTS. 


PART I. 


TREATS OF MANUFACTURE AND USE OF COKE — 
PROPERTIES IN ORES — OPERATIONS OF BLAST 
FURNACES —THE DIFFERENT BRANDS OF PIG 
IRON AND HOW TO PURCHASE AND USE THEM 
INTELLIGENTLY. 

CHAP. PAGE. 

1. The Manufacture and Properties of Coke,. i 

2. Properties of Ores used in Making Cast Iron.25 

3. Construction of Blast Furnaces,.. 34 

4. Lining and Drying Blast Furnaces,.40 

5. Operating Blast Furnaces and Reduction of Ores, ... 46 

6. Cause and Evils of Scaffolding and Slips in Furnaces, . 55 

7. Composition and Utility of Fluxes,.59 

8. Fluxing and Slagging out Blast Furnaces,.63 

9. Cold and Hot Blast vs. Combustion,.70 

10. Effects of Blast Temperatures in Driving Furnaces, . . 74 

11. Methods in Working Brick and Iron Stoves in Creating 

Hot Blast,.79 

12. Tapping out and Stopping up Furnaces and Cupolas, . . 89 

13. Moulding and Casting Sand and Chilled Cast Pig Iron 

and Open Sand Work,.99 

14. Making Chilled or Sandless Pig Iron and its Advantages, 113 

15. Utility of Direct Metal for Founding,.117 

16. Banking Furnaces and Cupolas,.121 

17. Constant and Changeable Metalloids in Making Iron, . .130 

18. Segregation of Iron at Furnace and Foundry,.134 

19. Mixing Furnace Casts of Pig Metal at Furnaces and 

Foundry,.. 





















IV 


TABLE OF CONTENTS. 


CHAP. PAOK. 

20. Different Kinds of Pig Iron Used and Definition of Brand 

and Grade,. *44 

21. Grading of Pig Iron by Analyses, . . # .148 

22. Difference in Utility of Bessemer from Foundry Iron for 

Making Castings. 157 

23. Charcoal vs. Coke and Anthracite Irons and some pe¬ 

culiar brands.160 

24. The Deceptive Appearances of Fractures in Pig Iron, . .163 
ln $. Impracticability of Hardness Tests for Grading Pig Iron, 175 

26. Origin and Utility of Standardized Drillings.180 

27. Intelligent Purchase and Sampling of Pig Iron, .... 194 

PART II. 

ELEMENTS IN CAST IRON AND THEIR PHYSICAL 
EFFECTS —UTILITY OF CHEMICAL ANALYSES 
AND HOW TO USE THEM IN MAKING THE DIF¬ 
FERENT MIXTURES OF IRONS USED IN MAKING 


GRAY AND CHILLED CASTINGS. 

CHAP. PAGE. 

28. The Metallic and Non-Metallic Elements of Cast Iron, . 202 

29. Chemical and Physical Properties of Cast Iron,.205 

30. Affinity of Iron for Sulphur and Its Strengthening- 

Effects, .223 

31. Effects of Adding Phosphorus to Molten Iron,.226 

32. Effects of Variation of Manganese in Different Irons, . 233 

33. Effects of Variations of Total Carbon in Iron,.246 

34. Evils of Excessive Impurities in Iron,.249 

35. Character of Specialties made of Cast Iron,. 252 

36. Methods for Calculating the Analyses of Mixtures, . . .255 

37. Effects of different Metalloids on Chilled Castings, . . . 258 

38. Mixtures for Chilled Rolls, Car Wheels, etc., . * . . . . 263 

39. Mixtures for Heavy and Medium Gray Iron Castings, . 273 

40. Mixtures for Light Machinery and Stove Plate Castings, 281 

41. Mixtures for Dynamos and other Electrical Work Cast¬ 

ings...284 

42. Mixtures for White Iron Castings and Effects of An¬ 

nealing.287 

43. Methods for Judging the Analyses of Scrap Iron, .... 292 

44. Analyses and Strength of Typical Foundry Iron Mixtures, 298 
















TABLE OF CONTENTS. 


V 


CHAP. 

45 - 

46. 

47 - 

48. 


PAGB. 

Chemical Changes made in Iron by Remelting it, . . „ 302 

Loss of Iron by Oxidation and Slagging out,.309 

Comparative Fusibility and the Melting Point of Differ¬ 
ent Irons,...323 

Aluminum Alloys in Cast Iron,. -.357 


PART III. 

PROPERTIES OF AND METHODS FOR TESTING 
MOLTEN IRON —DISCLOSES PHENOMENA IN THE 
ACTIONS OF COOLING METAL, ETC.—PRESENTS 
RESULTS OF TESTS IN ALL KINDS OF IRONS 
AND BEST METHODS FOR TESTING. 

CHAP. . PAGE. 

49. Methods for Melting Iron to Test its Physical Qualities, 362 

50. Judging of and Testing Molten Iron,.368 

51. Effects of Variations in the Fluidity of Metals,.372 

52. Specific Gravity of Vertical-Poured Castings,.377 

53. Expansion of Iron at the Moment of Solidification, . . . 382 

54. Effect of Expansion on Shrinkage and Contraction, . . 386 

55. Stretching Iron and Contraction Rules,.418 

56. Utility of Chill Tests, and Methods for Testing Hardness, 432 

57. Utility of Transverse, Crushing, Impact Tests, and 

Testing Car Wheels,.439 

58. Achieving Uniform Records and Utility of Tensile Tests, 449 

59. Contraction vs. Strength of Cast Iron,.451 

60. Comparison of Strength in Specialty Mixtures,.458 

61. Computation of the Relative Strength of Test Bars, . . 474 

62. Value of Micrometer Measurements in Testing.478 

63. Operating Testing Machines,.481 

64. Round vs. Square Test Bars,.483 

65. Evils of Casting Test Bars Flat.488 

66. Physical Tests for the Blast Furnace and their Value, . 495 

67. Appliances and Methods for Casting Test Bars.512 

68. Moulding, Swabbing, and Pouring Test Bars.523 

69. Utility of the Test Bar— Standard Methods for Testing, 528 

70. Methods of Casting and Compilation of Results of Amer¬ 

ican Foundrymen’s Association’s Tests,.539 

71. A Process for Brazing Cast Iron, and Etching,.585 



















VI 


Table of contents. 


SELECTED TABLES OF UTILITY FOR FURNACE AND 

FOUNDRY WORK. 


TABLE. PAGE. 

128. Net Weight of Sand Pig per Ton of 2,268 pounds, . . . 589 

129. Net Weight of Chilled Pig Iron per Ton of 2,240 pounds, 590 

130. Chemical Symbols and Atomic Weights, . . . . . . . 591 

131. Value in Degrees of Centigrade for Each 100 Degrees 

Fahr.,. 59 * 

132. Units of Heat and Heat of Combustion.592 

133. Scale of Temperatures by Color of Iron,.592 

134. Melting Point of Metals.593 

135. Relative Conductivity of Metals for Heat and Electricity, 593 

136. Specific Gravity and Weight of Metals, per Cubic Inch 593 

137. Ultimate Resistance of Metals to Tension in Pounds 

per Square Inch.594 

138. Strength of Different Kinds of Woods,.594 

139. Decimal Equivalents of Fractions of an Inch,.594 

Index. 59^ to 627 










PREFACE TO FIRST AND SECOND 

EDITIONS.* 


This work is written with a view to its value not 
only to the founder, the moulder, the blast furnace - 
man, the chemist, and the engineer, but also to the 
designer, the draftsman, the pattern-maker, the college 
specialist, and all that may in any manner be desirous 
of obtaining a practical knowledge of cast iron in its 
application to founding or any allied interests.* 

In compiling this volume, the author has been guided 
by a broad experience as a moulder and founder in 
loam, dry, and green sand work, in the various special¬ 
ties of founding, all of which require a knowledge of 
the subject as a whole in order to arrive at correct 
conclusions on questions pertaining to cast iron. 

A factor which has also aided the author in 
presenting this volume is that of being since 1892 
surrounded, in his present foundry location, by blast 
furnaces, thus affording him every opportunity of 
making a close study of modern furnace methods and 
the principles involved in making iron. This has also 
enabled the author, as a foundryman, to determine 
wherein many principles involved in furnace practice 
can often be well utilized in constructing and operating 
cupolas, as well as in mixing iron. 


* Preface to Third Edition is found on page xiii. 




viii PREFACE TO FIRST ANT) SECOND EDITIONS. 

In many respects this work will be found to be in 
advance of general practice, presenting many new 
subjects, principles, and ideas calculated to greatly 
broaden practical literature upon the metallurgy of 
cast iron, but the author does not advocate any meas¬ 
ures that have not been thoroughly tested by experience 
or a close study of the subjects presented. While this 
work will be found largely the product of the author’s 
own experience and research, he has also drawn upon 
the work of others wherever, in his judgment, this 
could in any way prove of practical value in giving a 
completeness to the various subjects treated. 

This work contains illustrations of valuable appli¬ 
ances which the author has originated and upon which 
he could have secured patents, but believing the ad¬ 
vancement of founding best aided by their being 
given freely to any that desire to use them, all are at 
liberty to freely utilize the various improvements 
shown. 

About a dozen of the chapters are revised extracts 
of papers which were presented by the author before 
the British Iron and Steel Institute, the American 
Society of Mechanical Engineers, the American Insti¬ 
tute of Mining Engineers, and the Eastern and West¬ 
ern Foundrymen’s Associations. The leading trade 
papers of America and Europe are also to be credited 
with having given first publicity to some of the 
author’s writings herein presented. Among those to 
be mentioned are the American Machinist , the Iron 
Age , the Iron Trade Review , and the Foundry —- 
American publications; and Engineering , of London, 
The Engineer , of Glasgow, and other leading trade 
papers of Europe. To all these associations and trade 


PREFACE TO FIRST AND SECOND EDITIONS. 


IX 


papers the author tenders his thanks. The encourage¬ 
ment thus rendered has served to stimulate the 
completion of this work, which has taken about 
four years to compile, due to the experiments, 
research, etc., found necessary in order to advance the 
original information presented. The result has been 
to bring all the author’s writings on the various sub¬ 
jects treated under one cover, giving to the reader an 
advantage that could not be otherwise obtained. 

The first and second editions are divided into four 
parts (the third edition is divided into three parts, as 
explained in the foot-note), the first illustrating the 
principles involved in a general way in the making of 
iron, commencing with a very complete chapter on 
coke and its kin, iron ore, followed by a description of 
furnace methods and principles which can often be 
well applied to cupola practice. 

The second part of the first and second editions 
treats of cupola practice, showing the latest improve¬ 
ments. It illustrates all the known methods for the 
application of “center blast,” accompanied with 
information on cupola practice necessary to be used 
with the author’s first two volumes to give a complete 
presentation of the subject up to date.* 

The third part in the first and second editions (now 
the second part in the third edition) is devoted to 
instructions of chemistry in founding, and clearly illus¬ 
trates the requirements of a wholly different practice 

* The chapters on cupolas in the second part were all transferred 
to “ Moulder’s Text Book” after the publication of the second 
edition. This caused the third edition to be divided into three 
parts, as shown by Table of Contents, also Preface to Third 
Edition, page xiii. 



X 


PREFACE TO FIRST AND SECOND EDITIONS. 


than has been followed to about the year 1895 by most 
founders, namely, of judging pig iron for mixture by 
its fracture, a quality which chemistry has proven to 
be wholly impractical. It shows the founder following 
such methods, why he cannot expect to meet with other 
than bad, undesirable results as well as heavy losses. 
It teaches how the greatest possible economy and 
desired ends in making mixtures are best achieved. 
It also defines, for practical application in the various 
specialties, the affinity which one chemical property or 
metalloid has for another in changing the character or 
grade of iron, and discloses valuable information on 
the science of mixing and melting cast iron. 

The fourth part of the first and second editions (now 
the third part of the third edition) is devoted to the 
subject of testing, and discloses new discoveries made 
by the author which explain causes for erratic results 
heretofore obtained for the most part from trans¬ 
verse and tensile tests, contraction chill, etc., recorded 
from bars of like area poured from the same ladle 
and gate, and presents methods best calculated to 
reduce erratic results to the least possible mini¬ 
mum. 

Following the seventieth chapter (seventy-first chap¬ 
ter, third edition), the work is closed with a few tables 
and an index. The first table gives the net weight of 
pig iron in gross tons of 2,268 pounds, ranging from 
one to one hundred tons. (The third edition gives a 
table of 2,240 pounds for figuring chilled pig.) The 
second table presents the full names of chemical prop¬ 
erties in metal, accompanied with their abbreviations 
or symbols as generally written by chemists. The 
tables following are copied from Messrs. Cremer and 


PREFACE TO FIRST ANI) SECOND EDITIONS. XI 

Bicknell’s “ Handbook for Chemical and Metallurgical 
Practice. 

It is not intended that this preface shall convey a 
complete statement concerning the importance of all 
the subjects treated. In order to obtain further con¬ 
ception of the important subjects discussed in the 
various parts of the work, the reader is kindly referred 
to a close study of the table of contents. 

Thos. D. West. 


Sharpsville, Pa., Jan. 5, 1897. 








PREFACE TO THIRD EDITION. 


A comparison of this third edition with the two pre¬ 
vious ones shows that this work has been extensively 
revised and enriched by the addition of much new 
matter on making, mixing, melting and testing of 
cast iron, part of which constitutes twenty new chap¬ 
ters embodying researches, experiences, experiments, 
discoveries, and illustrations that have been secured 
by the author since the publication of the first edition 
in 1897. To provide space for this large addition of 
new matter thirteen chapters treating of cupola prac¬ 
tice, published in the first two editions, have been 
transferred to the “Moulder’s Text Book,” leaving 
this work to the treatment of subjects more appropriate 
to its title, dividing the third edition into three parts 
instead of four, as in the first and second editions. 
For information on the special subjects treated in this 
work, readers are referred to the preface of first and 
second editions which precedes this, and also retained 
as originally written to assist in illustrating the changes 
made in the third edition. 

The author’s original researches, experiments, and 
discoveries described in this work involved an out¬ 
lay of much time and money, and he is indebted to a 
number of individuals for their valuable assistance in 
making chemical analyses, etc., and who have received 




Xiv PREFACE TO THIRD EDITION. 

I 

proper credit throughout the work. The melting and 
physical testing was chiefly done by the author, or 
under his supervision, as he advocates that all inves¬ 
tigators should do their own experimenting or other 
work as far as possible. 

There are a few works, in almost all epochs, that are 
so original and in advance of the times in their treat¬ 
ment and advocacy of new methods and suggested 
improvements, that it requires a lapse of several years 
to test their utility. The sales of some never exceed 
their first edition, while others, by force of merit, live 
and are recognized as standards, receiving much credit 
for their utility and praise for the benefits they render. 
This work belongs to the latter class and has met with 
a success that is very gratifying, as the reforms and 
new-school practices of mixing metals, by utilizing 
chemistry, testing, etc., advanced by the author in 
the first two editions are to-day, 1901, adopted and 
highly praised by a large number of those interested in 
the making and use of cast iron. About 25 per cent, 
of our present founders still follow the old-school 
practices, and to further influence some toward an 
adoption of the methods advanced in this work the 
author is pleased to present the following extracts 
seen on the next two pages from a few of many testi¬ 
monials tendered him during the year 1901. 

October, 1901. Thos - D ‘ West - 


ISSUE OF FOURTH EDITION. 

Preannouncement of the issue of the third edition so 
rapidly exhausted it, that this fourth edition was found 
necessary before trade papers, etc., could announce 
and review the third edition, Thos . d West _ 

January, 1902. 





PREFACE TO FIFTH EDITION. 


The first edition of this work, which can, in its 
present form, be justly called a practical compilation of 
original research, was issued sooner than it would have 
been, had not the author been anxious to combat and 
thwart impractical theories and practices that some in¬ 
experienced in general founding were laboring to 
establish, and which can be found in past records of 
trade papers and engineering societies, etc., and are 
now proven to be incorrect. The original information 
and reforms advanced in this work were too far m ad¬ 
vance of the times to escape severe criticism or insure 
the popular support they were entitled to, but are now 
receiving in such measure as to be very gratifying to the 
author. The impractical theories and practices that 
were advanced are not yet all set aside or acknowledged 
to be wrong and injurious as they should be by their 
advocates. However, the exhaustion of the third and 
fourth editions of this work in the short period of two 
months is a strong endorsement of the original practices, 
reforms, etc., advanced, and its practical utility. Time 
will demonstrate to all those not yet convinced of 
the impracticability of past teachings what is correct. 

Not only does the large sale of this work demon¬ 
strate its growing popularity, but also forcibly illus¬ 
trates the advancement of founders to accept its 





XVI 


PREFACE TO FIFTH EDITION. 


advocacy of chemical analyses, etc., in mixing metal 
instead of judging pig iron by the appearance of its 
fracture. One class of castings (ingot moulds) made 
by the firm of which the author is the manager, is 
subjected to the most rigid tests, when in use, that 
castings can be put to. In making these castings, an 
excellent opportunity is afforded to test the utility of 
working by chemical analyses. There are about half 
a dozen ingot mould makers in the United States and 
all of them will agree with the author when he asserts 
that being guided by chemical analyses instead of pig 
iron fractures has increased the efficiency of ingot 
mould service over fifty per cent. Manufacturers of 
other lines of castings can find similar and other 
benefits by the adoption of chemistry and following 
the teachings of this work. We have other works and 
writings showing effects of the carbons, silicon, sulphur, 
manganese, phosphorus, etc., in changing the character 
of iron, but they fail in not setting forth essentials that 
must be followed in order to make chemistry a success in 
founding or insure the greatest certainty and economy 
in obtaining desired mixtures of iron. The work has 
been said to be too large; but not until certain imprac¬ 
tical theories and practices have been entirely set aside 
can it be abridged or parts cut out. 

About one month after the issue of the third edition 
of this work Mr. W. J. Keep brought out a book entitled 
“ Cast Iron,” published by John Wiley & Sons, New 
York. On page 129 of this work he refers to a report 
made by a committee of the Western Foundrymen’s 
Association, in which preference was given to square 
bars cast flat instead of round bars cast on end, which 
had fluidity strips and chill attached to them. This 


PREFACE TO FIFTH EDITION. 


XVII 


was due to the lack of skill on the part of the molders 
and their inexperience in making such round bars on 
end. Why does Mr. Keep refer to the Chicago 
foundrymen’s local Association report and not to that 
of the national body (American Foundrymen’s Asso¬ 
ciation), accepted at Buffalo, June 1901, in which 
they recommend the use of round bars cast on end, and 
that bars should not be smaller than 1 y 2 inches diameter, 
as recorded on pages 574 to 584 of this work, and 
also still persist in advocating the use of J^-inch 
square bars with the evidence obtainable to prove their 
unfitness for testing cast iron. Good evidence of the 
unfitness of y 2 -inch square bars is presented by Mr. 
Keep in his book, “ Cast Iron, ” pages 173 and 174. 
Here we find that a slight difference in the fluidity 
of the same metal gave a difference of a hundred 
pounds in the body of two ^-inch square bars — a 
quality exactly in keeping with the evidence pre¬ 
sented in this work — showing how easily such small 
bars are made unreliable by slight variations in the 
temper or dampness of molding sand and temperature 
of pouring metal. 

Mr. Keep has presented tests in his work that were 
obtained by the American Foundrymen’s Association 
committee, but in so doing endeavors to carry along 
tests of the J^-inch bar also. The A. F. A. com¬ 
mittee found that a bar as small as f4-inch square or 
round was wholly unsuited to test any kind of iron, 
and hence totally ignored it in their recommendation, 
which was unanimously accepted by this national 
body, as stated above. It is to be regretted that men 
of inexperience in the actual work of broad molding 
or founding may be led to adopt incorrect practices, 








Xviii PREFACE TO FIFTH EDITION 

and that the general adoption of correct methods for 
testing cast iron is to be retarded by the advocacy of 
such an unreliable and impractical test bar as the 
y 2 -inch square. 

The author would not have embodied these remarks 
in a preface, did he not feel that events warranted them 
and he trusts it may be the means of doing some good in 
assisting to abolish an impractical and injurious 
practice. 

Thos. D. West, 

Sharpsville. Pa. February, 1902 


PREFACE TO SEVENTH EDITION. 

During the period intervening the publication of the 
revised third and the sixth editions, the demand has 
been such as to allow no time to make changes in the 
plates. Thus, a few errors remained in the revised 
work until the latter editions went to press. The few 
errors found, however, were, I am pleased to say, of 
such a character as not to injure the practical value of 
the work. 

The appreciation expressed by reviewers who have 
recommended this work to the public through the 
press, and by individuals, has done much to increase 
its popularity. I am not disregardful of these compli¬ 
ments tendered my work, and wish here to thank all 
those who have interested themselves in its behalf. 

Thos, D. West. 

Sharpsvillf, Pa., June, 1902. 

Eighth edition , issued May, /903. 

Ninth “ “ March , 1904. 

Tenth “ “ June , 1906. 



COMMENTS, 


Mr. W. G. Scott, Metallurgist and Chemist for J. I. 
Case T. M. Company, Racine, Wis., and laboratories 
at Philadelphia, Chicago, and Milwaukee, says of 
“ Metallurgy of Cast Iron “ Nearly every foundry- 
man has this work, and. I believe that it has done more 
to advance the science of founding than any work ever 
published. Since the appearance of this book there 
has been a notable change in foundry practice. The 
number of firms now mixing by analyses is astonish¬ 
ing, and I think that its author is entitled to the credit 
of starting the greater part of them on the modern 
plan, i.e., chemical metallurgy. I cannot say too much 
in praise of this book.” 

Mr. Frank L. Crobaugh, Proprietor and Expert, The 
Foundrymen’s Laboratory, Cleveland, O., and author 
“Methods of Chemical Analyses and Foundry Chem¬ 
istry” says: “ ‘The Metallurgy of Cast Iron’ has 
caused many advances in foundry practice, including 
the application of chemistry. 

Mr. Edgar S. Cook, President and General Manager 
of The Warwick Iron & Steel Co., Pottstown, Pa., 
says: “ I frequently hear the most complimentary 
remarks in regard to the beneficial influence of Mr. 
West’s papers, and especially with reference to his 
‘ Metallurgy of Cast Iron. ’ There is evidently a strong 
desire on the part of all interested in the subject, blast 




XX 


COMMENTS. 


furnace managers as well as progressive foundrymen, 
to arrive at some formula whereby guesswork may be 
replaced by certain well determined facts, and thus 
afford a safe foundation for scientific methods in 
foundry practice. Mr. West’s efforts in this direction 
are deserving of the widest recognition.” 

Mr. E. H. Putnam, Foundry Superintendent, Moline, 
Ill., and editor of the foundry department of The 
Tradesman , Chattanooga, Tenn., in writing of “ Metal¬ 
lurgy of Cast Iron ” says: “ I am glad to attest my 
appreciation of its great practical value. It is unsur¬ 
passed in foundry literature, and is an invaluable 
adjunct to the foundryman’s library.” 

Mr. Francis Schumann, the first president of the 
American Foundrymen’s Association, says: “ The 
foundry industry owes a lasting tribute to Thomas D. 
West for his efforts towards more comprehensive and 
rational methods in its processes. Mr. West holds the 
singular position of a foundryman engaged in the 
actual practice of his art, who, with ability, enthusi¬ 
asm, and zeal in original research imparts the knowl¬ 
edge so obtained freely and without reward. Much 
information is contained in his work of ‘ Metallurgy of 
Cast Iron ’ which cannot fail to interest found^rmen 
and engineers, touching, as it does, upon every stage 
from melting to the test bar. The work is of a kind 
that can come only from the practical founder about 
matters seldom found in print, because practical foun- 
drymen of Mr. West’s attainments are, as yet, a rarity. 


PART I. 









CHAPTER I. 


THE MANUFACTURE AND PROPERTIES 

OF COKE. 

The chemical and physical properties of fuel, having 
much to do with the physical and chemical properties 
of cast iron, when made or remelted, the author has 
thought that a general article on this subject would be 
very fitting in this work. Coke was first successfully 
used in this country at the Clinton Furnace, in Pitts¬ 
burg, in i860. Prior to this anthracite and bituminous 
coal, also charcoal, had been almost wholly used for 
smelting in furnaces; while anthracite coal was the 
chief fuel used by founders. In changing from the 
use of anthracite coal to coke for making and remelting 
iron, Pennsylvania and Ohio took the lead. It was 
not long until its use increased to such a degree that 
few are now found in this country depending on coal 
entirely as a fuel for making and remelting iron. Coke 
has forced its adoption for making iron mainly because 
it is a cheaper fuel, and for remelting iron because, 
aside from cheapness, it requires less blast and melts 
more quickly than coal. Coal, however, has still some 
advantages for remelting iron. 

The process of making coke consists of taking soft or 
bituminous coal and letting it burn for a number of 
hours in what are called coke ovens, generally of the 
form seen in Fig. 1. Other forms and methods are 


4 


METALLURGY OF CAST IRON. 


used, and some of them are covered by patents. Some 
of the advantages claimed for patent ovens are in the 
recovery of by-products and in saving labor and 
obtaining a greater yield of coke from the same amount 
of coal. 

The main principle in coking lies in admitting the 
air to support combustion at or over the surface, 
instead of causing it to pass through the coal as in 
burning fuel for firing boilers, etc., thus being an 
action of distillation more than of combustion. This 
prevents destruction of the coal while burning, and 
causes it to “ cake ” and become the coke of industrial 
commerce. 

The kind of ovens generally used in America is the 

bee-hive oven, as illustrated in Fig. i, page 8. Ovens 
are generally built from ten and one-half to twelve 
feet in diameter and from five to eight feet in height. 
The standard size is twelve feet in diameter and from six 
to eight feet high. Some are built on the plan seen in 
Fig. i. The interior of the oven is fire-brick, and the 
space between the ovens is packed with clay or loam. 
Pillars, as at K, are used for the support of the larries 
on the track B, so as to take their weight from the arch 
of the ovens. The outside of the ovens, as at S, are 
built of stone and made very strong. The filling is 
clay or loam, and the floor X is composed of tile 
fire-brick. 

Coal is sometimes coked in mounds, heaps, or piles 
similar to the method used for making charcoal of 
wood. It was by such method that coke was first 
made. By such methods of coking the coal must be 
chiefly in lumps, and piled in such a manner as to 
leave all the air space that is practical through the 


THE MANUFACTURE AND PROPERTIES OF COKE. 


5 


body of the mounds, and also piled so as to have as 
little of it touch the ground as possible. The mounds 
or piles are generally built around a brick chimney laid 
with loose bricks, left as full of holes in every other 
course of bricks as is practical, so as to provide open¬ 
ings for draft from the outside of the mounds at 
various heights. These piles range from fifteen to 
thirty feet in diameter, and from four to seven feet 
in height. They are set on fire by means of openings 
left in their bodies where wood and light brush can be 
inserted. Some piles are built in an oblong form, 
often running two hundred feet or more in length, with 
a base of twelve to fifteen feet in width. The plan of 
building such long piles is to lay a body of coal about 
sixteen inches high, then commence the formation of 
flues as seen in C, Fig. 2, page 10. These flues are 
filled with wood, brush, or any light kindling, and 
then set on fire at every opening, the aim being 
that no one part of the pile burn faster than another. 
If the fire should be too strong at any one point, the 
outside surface is banked with wet coke dust or earth, 
and applied to the whole surface of the structure as 
soon as the volatile matter has stopped burning so as 
to smother the fire and complete the coking of the coal. 
The last operation in this method of coking is to pour 
a little water down the vertical flues so as to diffuse 
steam throughout the entire body of the coke, which it 
is claimed is beneficial, resulting in the least moisture 
in the coke. It takes from five to eight days, accord¬ 
ing to the state of the weather, to perfect coking by 
this plan. The coke produced is said to be of very 
good quality, but as a general thing there is a consider¬ 
able loss in the yield where coal is coked in mounds or 


6 


METALLURGY OF CAST IRON. 


heaps, and the method has the disadvantage of requir¬ 
ing the coal to be in lump form. It is only where it is 
costly to secure building material, or where the coking 
qualities of coal are to be tested before expensive ovens 
are erected that mounds are used to coke coal at the 
present time. 

Coke has been found in a natural state. Appleton’s 
Encyclopedia cites a bed existing on both sides of the 
James River and near Richmond, Va. It is said to be 
hard, very uniform, and dark in color, but rather 
porous. It is claimed to be serviceable for melting 
purposes. 

By-product coke ovens have been erected by some 
firms owning steel plants, etc., whereby they can 
make their own coke at their works or at the mines. 
By this process, in connection with the by-products, 
such as gas, tar, and other substances produced, it is. 
claimed they can make a good profit on money invested 
and also be independent of the regular coke manufac¬ 
turers. It is said that out of one ton of coal ten thou¬ 
sand feet of gas can be produced, and out of fifteen 
hundred pounds of coke ninety to one hundred pounds 
of tar, with other by-products, can be produced. The 
gas from such ovens could prove of much value to 
some founders in drying moulds, cores, etc., and run¬ 
ning boilers. What coke the author has seen and used 
coming from by-product ovens is not as solid as the 
regular Connellsville coke, and it required a greater 
percentage of it to melt iron. 

In charging the bee=hive ovens enough coal is gen¬ 
erally carried by one larrie, A, to fill an oven at one 
charge. This larrie runs on a track over the top of 
the oven, as shown at B, Figs, i, 3, and 4. The latter 


THE MANUFACTURE AND PROPERTIES OF COKE. 


7 


two cuts are from an article by Mr. W. G. Irwin in 
Cassier's Magazine , January, 1901. The amount of 
coal charged into a bee-hive oven, as described here¬ 
with, covers the floor to a depth of about two feet for 
48-hour coke, and two and a half feet for 72-hour coke, 
and in weight ranges, according to the diameter of the 
oven, from three and one-half to six and one-half tons. 
By a handy dumping arrangement, the coal may be 
delivered to the ovens on either side of the track. 
After the coal has been dumped into the ovens through 
the hole E, it is leveled by means of a long-handled 
hook worked through the door at D. This done, the 
door is partially closed by means of bricks loosely laid 
and luted with clay or loam, an opening of about three 
inches being left at the top of the door for the admis¬ 
sion of air to support combustion in the oven. As the 
coking progresses the opening for the admission of air 
is gradually made less and eventually closed, in con¬ 
nection with the charging opening E, should the oven 
be carried over or burn off too soon. 

The coal is ignited by the heat which the ovens 
retain from the previous coking. A sharp draft is 
admitted as soon as the coal is ignited, which is about 
an hour after it is charged. A black smoke, combined 
with a greenish colored gas and occasional outbursts of 
flame, passes up through the charging hole E, which 
is left open to create a draft and permit the escape of all 
smoke and gases that may emanate from the coal. The 
gas which escapes has an odor sometimes strong of 
sulphur. The smoke generally ceases ten to twelve 
hours after the first ignition of the coal, after which a 
bright flame passes through the opening E and covers 
the entire surface of the coal, which by this time has 


FIG. I.—BEE-HIVE COKE OVEN 




























































































































































































































































































































THE MANUFACTURE AND PROPERTIES OE COKE. 


9 


attained almost a white heat. This process continues 
until the bright flame dies out, and then the coke is 
simply a red-hot mass containing not much more than 
one per cent of the volatile matter originally in the 
coal, the greater balance having passed off during the 
time in which the body of coal was raised to its 
highest temperature.- 

When the 48= and 72=hour coking period is com¬ 
pleted, or the oven is “ around,” a stream of water 
from a hose (or the water may be thrown from buckets) 
is sent over the surface of the glowing mass to extin¬ 
guish the fire. It is very important to cool off or stop 
all further combustion at this point of the coking, as, 
if permitted to continue burning, carbon would be 
consumed, thus causing a material loss of coke. 

Before drawing the coke, it is partly or wholly cooled 
off with water. The coal as it lies “caked,” or 
“ coked,” after being cooled in one solid mass, is full 
of vertical seams or cracks caused by the contraction. 
The cokers insert their hooks in these seams in draw¬ 
ing the coke from the ovens. It is landed on the coke 
wharves H, Fig. 1, from which it is loaded into cars 
standing on the track R and shipped broadcast to 
consumers, a perspective view of which is seen in 
Figs. 3 and 4, pages 12 and 21. The care exercised and 
the time taken in drawing the coke from the ovens has 
much to do with its size, freedom from “ braize,” or 
small coke, and the yield. Soon after the coke has 
been withdrawn, the oven is again filled with a charge 
of coal, the drawing door closed, and the heat of the 
oven from the previous coking, as above stated, ignites 
the fresh coal and the coking process is again started. 
Some manufacturers have followed the practice of 




Ground JPZan. 


FIG. 2.—COKING IN MOUNDS, 








































































































































































































































































THE MANUFACTURE AND PROPERTIES OF COKE. II 

drawing the coke from the ovens before cooling it off 
with water. The method of cooling the coke on the 
inside is hard on the brick composing the interior, but 
it makes a brighter coke and more comfortable work 
for the cokers. In so far as it relates to the question 
of moisture in coke, the product absorbs less moisture 
when cooled off in the inside than outside of the ovens. 

Some coke holds water to the extent of fifteen to 
twenty per cent of its own weight. Good fresh coke 
should not possess much over one per cent of moisture 
when protected from rain and snow. As it takes about 
fifteen pounds of coke in a cupola to evaporate one 
pound of water, it is evident that the less moisture a 
coke contains the less fuel required in melting, etc. 
Some firms recognize this factor and build stock houses 
so as to keep coke under cover. It is claimed that 
exposing coke to outdoor weather will reduce sulphur. 
To what extent this is true has never been demon¬ 
strated. 

Coal is sometimes of such poor quality, or full of 

slate or iron pyrites, that it must undergo a process 
of washing before it can be charged into the oven to 
be coked. The method of treatment consists in crush¬ 
ing the coal, if it is in lump form, so as to make it as 
fine as slack. It is then carried by means of buckets 
attached to an endless chain from boat, car, or crushers 
to tubs of water, so arranged with “ jiggers ” that a 
constant agitation and flow of water causes the differ¬ 
ent bodies in the coal to take their place in the water 
according to their several specific gravities. The 
pyrites and slate, being heaviest, sink to the bottom, 
and by a series of jogging tubs through which the coal 
is passed, the floating bodies — the coal partially freed 



FIG. 3.—DRAWING COKE FROM AN OVEN. 








the manufacture and properties of coke. 


x 3 


from its pyrites and slate — are caught by perforated 
iron buckets on an endless chain and carried to a stock 
pile or to the larries, then to the ovens to be chareed 

o 

for coking. The impurities in the form of slate and 
iron pyrites which have sunk to the bottom, are passed 
along through the shutes with outflowing water to the 
refuse bed. The washing process often removes 
bitumen with the slate to such a degree as to rob the 
coal greatly of its coking qualities. 

The yield of coke obtained from ovens generally 
ranges from sixty to seventy per cent of the coal 
charged, whereas the yield from heaps or mounds 
does not exceed fifty to fifty-five per cent. The long 
mounds are said to be productive of better coke and 
furnish a larger yield than round or small oblong piles 
having one center draft provision. The following table 
No. i shows the yield of a few grades of Connells- 
ville coke in ovens prepared by Mr. John Fulton, and 
published in the American Manufacturer of February 
io, 1893: 

TABLE I.—YIELD OF COKE FROM COAL. 


No. of test. 

Time in. 
oven. 

Coal 

charged. 

Ash made. 

Fine coke 
made. 

Market coke 
made. 

Total coke 
made. 

Per cent, of yield. 

Per cent, lost 

Ash. 

Fine 

coke. 

Market 

coke. 

Total 

coke. 


h. m. 

lb. 

lb. 

lb. 

lb. 

lb. 






1 

67 00 

12,420 

99 

385 

7 , 5 iS 

7,903 

00.80 

3.10 

60.53 

63-63 

35-57 

2 

68 00 

11,090 

90 

359 

6,580 

6,939 

00.81 

3-24 

59-33 

62.57 

36.62 

3 

45 00 

9,120 

77 

272 

5 4i8 

5,690 

00.84 

2.98 

59-41 

62.39 

36-77 

4 

45 00 

9,020 

74 

349 

5,334 

5,683 

00.82 

3-87 

59-13 

63.00 

36.18 



41,650 

340 

1,365 

24,850 

26,215 

00.82 

3.28 

59.66 

62.94 

36.24 


The question of density in coke is largely one of cell 
space, which can vary greatly in hard as well as in 
soft grades of coke. Oven coke is generally considered 







































14 


METALLURGY OF CAST IRON. 


to have a cell structure of about fifty per cent greater 
than exists in coal. The quality of hardness is one of 
much importance, especially in blast furnace practice, 
as the coke should possess a certain strength to sustain 
the weight of the stock which is charged on top of it. 
If it is not strong enough to resist the load, it can be 
crushed into a mass so compact as to prevent the free 
passage of blast through its body, which is necessary 
to create proper combustion and make the furnace 
work well. To a degree it has the same effect on 
passage of blast in cupolas. Then again a soft coke 
can crush so as to lower a bed, cause dull iron, and 
make a cupola bung up much more readily than hard 
coke. (vSee close of chapter.) Oven coke can be light 
and porous as well as heavy and dense, and is often 
spoken of as hard or soft. The terms hard and dense 
do not mean the same thing. Coke can be dense but 
soft. The following table, No. 2, of physical tests, by 
Mr. John Fulton, will illustrate the crushing strength 
of coke with other properties. A chemical analysis of 
the same coke by Mr. A. S. McCreath and Mr. T. T. 
Morrel is seen in Table 3, and which is taken from an 
article by the late Joseph D. Weeks of Pittsburg, 
which appeared in the Pennsylvania Annual Report of 
the vSecretary of Internal Affairs, 1893. In referring 
to the coke tested, Mr. Fulton says: “ These tests 
show a compact, hard-bodied coke, harder than the 
average Connellsville standard. This coke has been 
carefully prepared and cannot be distinguished from 
Connellsville coke. The cells are a little less than the 
Connellsville, but the difference is not large enough to 
induce any marked change in blast furnace. It has 
proved an excellent fuel for this and kindred uses. ’ ’ 


THE MANUFACTURE AND PROPERTIES OF COKE. 15 

Table 4 is an average of several analyses of coke from 
the Connellsville region. The author has used this 
coke extensively at his foundry and has found it to be 
a fair grade of coke. 

TABLE 2.—SEVENTY-TWO HOUR COKE. 



TABLE 3.—CHEMICAL ANALYSES. 


Locality. 

Fixed 

Carb. 

Mois. 

Ash. 

Sulph. 

Phos. 

Volatile 

matter. 

Standard coke, Connells¬ 
ville . 

87.46 

88.476 

0.49 

. 148 

11.32 

9-73 1 

0.69 

•95i 

0.029 

.008 

O.OII 

.692 

Walston coke, (A. S. Me 
Creath 72-hour coke). 


TABLE 4. 


Moisture. °58 

Volatile matter.634 

Fixed carbon. 9°-754 

Ash. 8-554 


Sulphur. 

Phosphorus 


JOO.OOO 

.790 

.014 
























































Forty-eight-hour and 72-hour coke refers to the time 

the coal is subjected to the coking process in the oven. 
Table 1, page 13, shows that 48-hour and 72-hour coke 
varies in the length of time it is in an oven, and that 
the actual time coal is coked is largely regulated by 
local conditions best suiting the working convenience 
of the coke workers in going the rounds of their ovens; 
and we might say we have instead of 48-hour and 
7 2-hour coke, two- and three-day coke. Where ma¬ 
chinery is used instead of mules and hand labor in 
charging ovens, the coal is insured a longer coking 
than forty-eight and seventy-two hours, as by the 
means of machinery the ovens can be charged earlier 
in the day and the coking resumed. Seventy-two hour 
coke, which is used chiefly by foundrymen, is gener¬ 
ally due to coke remaining in the ovens over Sunday, 
which day the cokers do not work. Seventy-two 
hour coke is not always up to the high standard that 
many claim for it. The author has melted with 
furnace, or 48-hour coke, for six months at a time, 
and he cannot say that the fact of its being 48- 
hour coke caused it to be unsatisfactory, when the 
difference in price was considered. Nevertheless, 
as a rule, 48-hour coke is of less value as a 
melter than 7 2-hour coke, as the latter is generally a 
harder, larger, and cleaner fuel. As large a coke may 
be produced from a 48-hour as a 7 2-hour burning, but 
owing to the conditions which permit furnacemen to 
use smaller and more dusty coke with less evil results 
than are apt to follow its use in cupola work, 48-hour 
coke is not selected nor handled with the same care as 
7 2-hour coke, and hence the former will give a greater 
yield from the same amount of coal. The method used 


THE MANUFACTURE AND PROPERTIES OF COKE. 17 

for obtaining the best “ selected ” coke is that of cool¬ 
ing off the coke inside the ovens and in picking out the 
black ends and fine as well as poorly burned coke. 
There are times when coke is burned from ninety-six 
to one hundred and twenty hours, and then again only 
coked twenty-four hours in bee-hive ovens; but this 
latter product is generally not suited for making or 
melting iron. It is said that if coke makers take the 
precaution, they can make 24-hour coke nearly as good 
as the 48-hour article, with the exception of its not 
being quite as long in its body. 

Gas house coke is obtained from the retorts used in 
gas works to produce illuminating gas, or from the 
retorts used in manufacturing coal-tar or other by¬ 
products. vSome kinds of coal will produce gas coke 
by the use of which iron can be melted. Coal of the 
quality found in the Connellsville region is suitable 
for making this coke. When gas, or soft coke, is used 
for melting it is often necessary to use double the quan¬ 
tity or number of bushels than of hard oven coke, and 
at its best it is an undesirable fuel for this purpose. 
It will often give good satisfaction in drying cores or 
moulds, and work even better than hard coke, but 
much more of it must generally be used than of the 
oven, or hard coke. 

Comparison of Connel!svil!e coke with others has 

shown that the opinion held by many that Connells¬ 
ville coke could not be equalled, was an error. The 
localities shown in Table 5, by Mr. John R. Proctor, 
published in the, Kentucky Geological Survey Report, 
are furnishing considerable good coke to furnacemen 
and founders. 


l8 METALLURGY OF CAST IRON. 


TABLE 5.—ANALYSES OF COKE FROM DIFFERENT LOCALITIES. 


Where Made. 

• 

Fixed 

carbon. 

Ash. 

Sulphur. 

Connellsville, Pa. (Average of 3 samples.). 

Chattanooga, Tenn. “ “ 4 “ . 

Birmingham, Ala. “ “ 4 “ . 

Pocahontas, Va. “ “ 3 “ . 

New River, W. Va. “ “ 3 “ . 

Big Stone Gap, Ky. “ “ 7 “ . 

88.96 
80.61 
87.29 

92.53 

92.38 

93-23 

9-74 

16.34 

10.54 

5-74 

7.21 

5-69 

0.810 

x -595 

1 -195 
0-597 
0.562 
0.749 


Coke of a silvery metallic lustre and possessing a 
solid, hard body, with cells well connected and of uni¬ 
form structure, can generally be called “ good coke.” 
The hidden element that might do serious harm in 
such coke is sulphur or phosphorus, for these can be 
high or low in any grade of coke. This can only be 
properly determined by analysis. The coke generally 
condemned by the consumer, especially the founder, 
is small sized coke, mixed with ash cinder or coke 
dust; then again coke that is dark in its general 
appearance, having black ends, and soft in quality. 
Even when the coke has all other commendable quali¬ 
ties but is in small pieces, such is often sufficient to 
produce bad results in melting iron. Then again coke 
may not possess the much desired “ silvery or bright 
metallic lustre” and still be good, if it is only large 
and hard in character, possessing a good cellular 
structure. The harder or more dense the coke, the 
stronger blast is required in melting iron. 

Black ends are of two kinds. One is called black 
tops and the other black butts, the latter coming from 
the bottom of the charge of coal as it lays in an oven, 
and the former from the top. Black tops are rarely 
injurious, while black butts can be. These latter may 
often be caused by reason of an inch or more of the 






















THE MANUFACTURE AND PROPERTIES OF COKE. 19 

coal lying on the bottom of a cold or hot oven being 
uncoked or fused. The coking process proceeds from 
the top of a charge. There are times when the heat 
of the crown of a very hot oven may fuse the top sur¬ 
face of the coal and form a thin crust or film which will 
prevent the usual freedom in the escape of gases. 
These being held back for a time, will deposit a soot 
or lampblack in the cells of the forming coke so as to 
result in giving black tops, or a black coke. As soon 
as the gases gain sufficient pressure to burst through 
the top crust or film, then the deposit of sooty matter 
ceases. 

Stock coke is generally of a smaller size than that 
conveyed directly from ovens to cars for shipment, 
for the reason that it is broken up by extra handling. 
It is called stock coke for the reason that it is coke 
that, for want of orders or cars to make shipment, has 
to be stored in large piles at the coke works — some¬ 
times months and sometimes years. Lying thus it is 
subjected to rain, snow, dust, and smoke, collects 
excessive moisture, and becomes dirty. Sometimes, 
in order to keep the ovens going and save stocking, 
heavy charges are resorted to and the coal coked from 
ninety-six to one hundred and twenty hours. This 
process causes a loss of coke in the ovens. 

The fixed carbon in coke used for furnace and foun¬ 
dry work generally ranges from eighty to ninety per 
cent. Sometimes it is considerably under this, and 
occasionally it may exceed the highest limits by two 
to five per cent. Some of the carbon is lost by the 
process of coking. If cooled by water at the proper 
time the percentage lost is rarely very large. When 
more than from two to four per cent of carbon is lost, 


20 


METALLURGY OF CAST IRON. 


either the coal is inferior to Connellsville coal or it has 
not been treated properly, and the coke has been 
allowed to waste. The amount of loss is due to sev¬ 
eral factors. One may be the indisposition of the coal 
to coke, and again it may be the fault of the ovens and 
their treatment. 

The ash in coke is an impurity which, like phos¬ 
phorus and sulphur, lessens the commercial value of 
the coke as the percentages increase. The ash in fur¬ 
nace and foundry coke generally ranges from nine to 
fourteen per cent. It may exceed this two to four per 
cent, or be as low as five per cent. The ash of coke 
generally includes the impurities found in Table 6, 
obtained by Mr. E. C. Pechin. The less ash coke 
contains the greater is its value, generally speaking, 
although very low ash is not desirable in all cases. It 
is often beneficial in assisting the formation of a good 
slag. The coke made from washed coal contains less 
ash and sulphur than that made from unwashed coal. 

TABLE 6.—ANALYSES OF ASH IN CONNELLSVILLE COKE. 


Alumina. 3.262 

Sesquioxide of iron. 0.479 

Lime. 0.243 

Magnesia. 0.007 

Phosphoric acid. 0.012 

Potash and soda.Traces. 


9.416 

The chemical properties desirable in coke are, first, 
low sulphur and often low phosphorus, and second, 
high carbon. As a rule when adopting a new brand 
of coke, and often in the use of old ones, it will pay a 
founder to assure himself as to the chemical properties 
of the coke before using it. This is a practice which 










THE MANUFACTURE AND PROPERTIES OF CORFU 


2 I 

furnacemen generally follow. In sampling coke for 
analysis much more should be selected than is actually 



required, and the sample obtained should be carefully 
picked from different parts of a pile or car. 

High sulphur in coke may lead to very serious results 













22 


METALLURGY OF CAST IRON. 


in founding as well as in furnace work. It is generally 
very essential in making coke that plenty of pure water 
be had. A drought can make water so scarce as to 
compel the use of mine water. Such usually contains 
enough sulphur to seriously affect the coke when 
quenching the fire. The process of coking has much 
to do in controlling the amount of sulphur in coke. 
Coke from the same mine and oven can and often does 
vary greatly in the percentage of sulphur. If sulphur 
is above .90 per cent it can often be told by the odor of 
escaping gases and the stifling fumes a furnace or 
cupola will emit, as compared with coke below .80 
per cent. High sulphur can often be detected by 
the eye, due to its causing yellow spots or stains to 
appear on the surface of the coke. A quick test is 
made by heating pieces red-hot and dropping them 
into a pail of water. This drives off the sulphur to 
such a degree that, with a little practice, one can detect 
differences in the amount of sulphur coke may hold. 
The best way, of course, to determine the sulphur or 
other properties, is by chemical analysis. 

Phosphorus in coke may be injurious and then again 
beneficial to both furnacemen and founders. This 
depends upon the percentage of phosphorus desired in 
any special brand or mixture of iron, as whatever phos¬ 
phorus coke contains is generally taken up by the iron 
when being made or remelted. If, for example, regu¬ 
lar Bessemer iron or castings calling for phosphorus 
not exceeding .10 is desired, the high phosphorus coke 
would certainly be injurious; but if it is foundry iron 
that is desired to make thin castings, then higher 
phosphorus coke is essential, as increasing, phosphorus 
increases fluidity, see page 216. It always requires 


THE MANUFACTURE AND PROPERTIES OF COKE. 23 

chemical analysis to detect the phosphorus while the 
eye may at times detect the sulphur. 

The best brand or grade of coke to use in smelting 
or melting iron is often regulated by its cost. Certain 
localities in the Connellsville region are generally 
conceded to give the best grades of coke to be found 
in this country, but the great distance of many con¬ 
sumers from this point makes the cost so great that 
they use other brands. However, almost every locality 
can furnish different grades, and it is often surprising * 
how much less of the best grade is required than of 
poorer ones in doing the same work in melting. It is 
rare that there is any economy in using poor grades 
of coke if the difference in price is at all reasonable. 

In the first use of coke in cupolas it was bought and 
charged by the bushel, instead of by weight as at 
present. Coke weighs from thirty to seventy pounds 
per bushel, the more dense and hard, the heavier it is. 
In using coke in cupolas it is very important to note 
its hardness and be governed by the same, as with the 
same weight of coke in good soft and hard grades one 
can readily conceive that the bed and charges of coke 
would vary in height and could often cause trouble, as 
for example the same weight in a soft coke that would 
bring it up to eighteen inches or so above the top of 
the tuyeres, could, in hard coke, bring it only to a 
level of the tuyeres or a little above, which all experi¬ 
enced founders know would soon bung up or prevent 
a cupola from melting. Where one is called upon to 
use a soft -coke — and which will not permit cupolas 
to run as clean or as long as hard coke, although soft 
coke may give good hot iron—he should, as a rule, use 
less weight of the soft coke than of the hard in the bed 


24 


METALLURGY OF CAST IRON. 


and between charges, and at the same tim6 reduce the 
weight of the iron in both the bed and charges, as, if the 
same weight of soft as of hard coke found best is used, 
the bed of fuel would be raised above that point best 
for rapid and economical melting. It is to be under¬ 
stood that this does not mean that a less weight of soft 
coke will be required throughout the whole heat. Re¬ 
ducing the weight of iron on the bed of coke and 
between the charges calls for a greater number of 
charges of coke, as well as of iron, and thus may cause 
as much or a greater weight of soft coke to run off a 
heat than if hard coke had been used. When using 
soft grades of coke and following the above sugges¬ 
tions, the rule of charging three pounds of iron to one 
of coke on the bed and ten to one between the charges 
will often serve as a guide in decreasing the weight of 
iron to approximately correspond with the decrease in 
the weight of fuel that may be found best to adopt. 
This is assuming the height of tuyeres to be about 
eighteen inches above the bottom plate; with lower 
tuyeres three to five pounds of iron to one pound of 
coke may often be charged on a bed of coke. Where, 
by reason of coke being soft, dull iron is obtained, or 
the cupola bimgs up badly, such trouble may not only 
be decreased by making smaller charges of iron, but a 
milder blast is also generally desirable. A strong blast 
often blows all the life out of soft coke, facing the 
tuyeres, and often leaves a space that can fill up with 
chilled slag or iron droppings which can soon bung up 
or stop a cupola from melting. For further informa¬ 
tion on charging, etc., of cupolas, see American “ Foun¬ 
dry Practice ” and “Moulder’s Text Book.” 


CHAPTER II. 


PROPERTIES OF ORES USED IN MAKING 

CAST IRON. 

A brief description of elements in ores will point out 
varying qualities in the material from which cast iron 
is made, and also help impress one with the great 
difference ores can and do make in the different 
brands of iron. The ores from which cast iron is 
made are largely oxides of iron, containing other ele¬ 
ments and impurities, among which generally exist 
more or less manganese, sulphur, phosphorus, alumina, 
and silica. It is called “ rich ore ” when high in iron, 
and “ lean ore,” when low. The oxides of iron are 
known as “ ferric oxide ” and “ ferrous oxide.” The 
former, theoretically, contains 70 per cent of iron and 
30 per cent of oxygen, the latter 77.78 per cent of iron 
and 22.22 per cent oxygen. Percentages of iron and 
oxygen vary in the ores, but the above percentages 
constitute distinct chemical compositions. 

Many soils and rocks contain more or less oxide 
of iron, but such material is not generally considered 
suitable to make cast iron unless it contains more than 
30 per cent of iron. Ores are now very rarely used for 
making cast iron or pig metal unless they contain more 
than 40 per cent of iron. The ore used in the manu- 


26 


METALLURGY OF CAST IRON. 


facture of cast iron and worked to an economical advan¬ 
tage generally contains from 50 to 65 per cent of iron, 
and it is rare that ore of sufficient quantity to keep a 
furnace going steadily on a fair uniform product can 
be obtained containing more than 70 per cent of 
iron. 

The pig iron which the founder uses (barring ferro- 
silicon, etc.) generally contains from 92 to 96 per cent 
of metallic iron, with 4 to 8 per cent of impurities, 
chiefly carbon, silicon, manganese, sulphur, and phos¬ 
phorus. These impurities, while called such, are really 
the elements which make iron of any practical value 
in the various industries. According to changes in 
the proportions of these so-called impurities, we are 
given the different grades of pig iron so essential to 
meet varying conditions called for in our widely diver¬ 
sified use of iron. 

Silica ranges in ores from a trace to 20 per cent, 
and often higher. The ores generally used for . ordi¬ 
nary pig metals contain from 3 to 8 per cent of silica. 
Next to the iron in the ore. silica is the largest consti¬ 
tuent in nearly all ores used. The combined silica in 
the ores, fuel, and flux gives the silicon to the iron. 
Where high or ferro-silicon iron is desired, high silicious 
ores are used in 'connection with a greater amount of 
fuel and higher temperature in the furnace. With 
like fuels, ores, and fluxes the higher the temperature 
in a furnace, the higher silicon will be found in the 
iron. The higher the temperature desired, the more 
fuel it is necessary to use. Furnaces may work so cold 
by reduction of fuel, or bad working, as to cause the 
greater part of the silica to be carried off with the slag, 
instead of its making silicon in the iron. 


PROPERTIES OF ORES USED IN MAKING CAST IRON. 27 

Manganese is found in nearly all iron ores. It 

readily alloys with iron, and all the manganese con¬ 
tained in pig iron is obtained from the ores. Manga¬ 
nese occurs in ores in the form of manganese dioxide 
and manganese oxide. Some ores are so high in 
manganese that they are called manganiferous ores, 
and of late years their reduction has been achieved in 
blast furnaces about as readily as iron ore is reduced, 
although at one time it was thought impossible to 
obtain high manganese pig from a blast furnace. 

Ferro=manganese is obtained by smelting mangan¬ 
iferous ores in a blast furnace, and is placed on the 
market as a commercial product containing from 40 
per cent to 90 per cent of manganese. The standard 
contains from 79 to 81 per cent. 

Spiegeleisen or “Spiegel ” is a product of manganif¬ 
erous ores, but lower in manganese than ferro-manga- 
nese. It ranges from 7 per cent to 40 per cent of 
metallic manganese. The standard contains from 19 
to 21 percent. In this form it generally presents a 
silvery white fracture with a crystalline structure. By 
some this metal is called “ looking-glass iron,” the 
English translation of spiegeleisen. Spiegeleisen is 
readily produced, whenever sufficient manganese is 
present in the ore. Both these manganese metals are 
chiefly used in the manufacture of steel in its many 
and various grades. 

Phosphorus exists in most iron ores. Almost all the 
phosphorus contained in the ore, fuel and flux is 
reduced and absorbed by the metallic iron when 
smelting or remelting it. Low phosphorus ores are 
generally of greater value than high phosphorus ores. 
For Bessemer iron, in which phosphorus must not 


28 


METALLURGY OF CAST IRON. 


exceed .10, lower phosphorus ores must be used than 
in making foundry irons. It is often found beneficial 
to have pig iron contain as high as 1.50 phosphorus, 
owing to the fact that phosphorus possesses the quality 
of giving life and fluidity to molten metal, which is 
most desirable in running thin castings. 

For de=phosphorizing magnetic ores, different kinds 
of devices have 
been used. Fig. 5 
will convey an idea 
of the principles 
involved in the 
separation of “tail¬ 
ings” and “con¬ 
centrates ’’ bv the 

J 

employment of 
magnetic power. 

By the use of sepa¬ 
rators or magnets 
from 50 per cent 
to 80 per cent of 
the phosphor u s 
originally con¬ 
tained in ore is said to be removed. Magnetic 
ores which contain pyrites (which is a combination 
53-3 P er cent of sulphur with 46.7 per cent of iron) 
can have, it is also said, a larger per cent of their 
sulphur contents removed by magnetic concentra¬ 
tion with a separator than by roasting, as referred to 
below. Sometimes the sulphur is present in pyrrho- 
tite (which is 39.5 per cent of sulphur combined with 



60.5 per cent of iron) in which state experiments have 
shown that there would be as much sulphur in the con- 







PROPERTIES OF ORES USED IN MAKING CAST IRON. 29 

centrates as existed in the crude ores, and hence, sepa¬ 
rators to eliminate sulphur from this class of ore have 
proved a failure. 

High sulphur ores are sometimes subjected to a 
process called “roasting” or “calcination” which 
generally drives off a greater part of the sulphur. 

Varieties of iron ores are very numerous. In order 
to classify them they are chiefly placed under one or 
the other of the following heads: hematites, magne¬ 
tites, and carbonates. Of the first there are two kinds, 
known as the brown and red hematites. There is 
more red hematite used than all the other ores com¬ 
bined. Red hematite is generally quite free from 
sulphur, and it is found in almost every shape in which 
ore is found and exists in large quantities. Messaba 
ore, a soft ore now largely used to make both Besse¬ 
mer and foundry iron, is a red hematite which, it was 
thought, a few years ago, by experts, to be unsuited 
for the blast furnace on account of its being such a 
dusty, fine soil material. 

Magnetic ore is the next variety generally recognized 

in the order of classification. This ore is found in 
veins and is generally classed with the hard and 
refractory ores. It is generally a dense black material, 
which must be crushed or broken to suit the varying 
conditions of smelting. In Canada and New Zealand 
magnetic ore is found in the form of coarse gravel or 
•sand, which, as a rule, furnacemen prefer not to use if 
it can be avoided. Magnetic ores are often discovered 
by the attraction they exert upon the compass needle. 
They are often very free of phosphorus and sulphur, 
but if they are too high in phosphorus and sulphur 
they will not be used as long as sufficient ore of suit- 


3 ° 


METALLURGY OF CAST IRON. 


able grade can be obtained without the cost necessary 
to prepare objectionably high sulphur and phosphorus 
ore for smelting. 

Brown hematites include bog ores, which are found 
in shallow rivers, etc., and are now very little used; 
they are largely the result of the oxidation of the 
carbonates of iron. No ore is more irregular in its 
characteristic qualities. It may be of a yellow as well 
as a brown color. It is generally porous and easy to 
reduce and smelt in a blast furnace. It is found mixed 
in undue proportion with earthy and gangue matter 
and often rich in carbonate of lime, and is also gener¬ 
ally high in phosphorus. It is found in beds and 
veins and often forms the cover of copper ores. 

Carbonate and spathic ores are generally of a whitish 
color, but they are often found mixed with manganese, 
which turns them brown. They are largely found in 
massive veins of great thickness and in combination 
with other carbonates and may be of a greenish gray 
color. Brown hematites are also found existing in 
sands or soils of a coarse character. There is some 
dispute as to their value. Some claim that they excel 
red hematites for making high grade iron. A variety 
of carbonate of iron ores is known as clay iron stone 
by reason of its being found in the clay bands of the 
coal fields. This class of ore is largely used in Scot¬ 
land as well as in England. “Black band” is one 
variety of this class of ores, and is of a glossy black 
color. 

Black band ores give strong irons, and when mixed 
with soft hematite ores make a soft, or good grade of 
Scotch iron; but of late years they have become so 
scarce that they cannot compete with the more plen- 


PROPERTIES OF ORES USED IN MAKING CAST IRON. 31 

tiful ores, which can be made to produce an iron that 
will be accepted in some cases as equally satisfactory. 
An ore approaching-black band, and called “ band iron 
stone, ’ ’ is now often used. This is of a bluish gray 
color, and exists in coal formations similar to black 
bands. Some of th£se ores are smelted in their raw 
state, while others are roasted and converted into 
higher oxides before being smelted. 

Titaniferous ores, free of sulphur and phosphorus, 
containing io to 16 per cent of titanium and 50 to 60 
per cent iron, found in the Adirondack mountains, are 
now being used to make ferro-titanium by the Ferro- 
Titanium Co., Niagara Falls, N. Y., Mr. A. J. Rossi 
being the inventor of the process. Nearly half the 
ores found on this continent contain more or less 
titanium, but furnacemen have always found it most 
difficult to use titaniferous ores on account of the 
titanic acid making an infusible slag. Since Mr. Rossi 
has lately succeeded (January, 1901) in overcoming this 
difficulty, it is rather early to predict to what extent 
this ferro-titanium may prove of value to steel manu¬ 
facturers and founders, as titanium is known to 
strengthen or chill iron by holding the carbon more in 
a combined form, similar as with manganese and 
sulphur. 

Mill cinder iron is a grade of metal derived from the 
smelting of rolling mill cinder exclusively, or in admix¬ 
ture with iron ores. Rolling mill cinder can be classed 
under the heads of puddle, tap cinder, heating furnace, 
flue cinder, roll cinder, and bosh cinder; the latter 
being collected in a trough or bosh of water in which 
the puddlers cool their tools. Roll scale is generally 
supposed to contain the most iron, followed in order 


3 2 


METALLURGY OF CAST IRON. 


by bosh, tap, and flue cinder. Mill cinder is generally 
used first because it can often be purchased for about 
one-half the price of iron ore and because it often con¬ 
tains a large percentage of iron. 

Tap cinder is of two varieties, one is “boilings” 
that flow over the floor plate of a puddling furnace 
when making the iron, and the other is “ tappings ” 
that runs out of a furnace at the end of the heat. As 
a general thing boilings are very much higher in phos¬ 
phorus and silica than tappings. Mill cinder, as above 
outlined, is composed largely of protoxide of iron and 
silica. It contains, at times, ferric and magnetic 
oxides and is generally high in phosphorus. Table 9 
is an analysis of four samples of mill cinder which the 
author secured to give an idea of the chemical compo¬ 
sition of the same. As it would take about two tons 
of such cinder to make one ton of iron, there would be 
about twice the amount of phosphorus in the iron 
produced than is contained in the cinder ore where all 
cinder was used. 


TABLE 9. -ANALYSIS OF MILL CINDER. 



1 . 

2 . 

3- 

4- 

Iron. 

52.48 

52.20 

52-91 

53-70 

Phosphorus. 

1.32 

•34 

•47 

•37 

Silica. 

24.65 

25.06 

23-43 

23-39 

Manganese. 

•34 

•45 

•57 

•35 


Iron mill cinder is only used for making foundry or 
mill iron. It is not used for making Bessemer for the 
reason that it would raise the phosphorus too high, 
which for foundry iron is not so objectionable; in fact, 
foundry iron often requires high phosphorus. It can 
be said that a few are now using steel cinder in making 




















PROPERTIES OF ORES USED IN MAKING CAST IRON 33 

Bessemer iron, owing to such being very low in phos¬ 
phorus. Aside from the iron being low (see Chapter 
XXXIV.), it is mainly the phosphorus that is to be 
feared in mill cinder iron, as this cannot well be elim¬ 
inated. If the “iron” is lower and the phosphorus 
higher than is beneficial in pig metal there are grounds 
for rejecting it, but otherwise the foundryman is rarely 
justified in condemning mill cinder mixed pig iron on 
the ground that it contains slag because cinder wa-s 
used in making the iron, until he has tested it to have 
a knowledge of its chemical constituents and physical 
properties. Founders have used mill cinder mixed 
pig iron when they thought there had not been an 
ounce of cinder mixed with the ore. Not only is mill 
cinder mixed with ores, but a furnace has been kept 
going steadily making pig metal with simply all mill 
cinder. Mr. C. I. Rader has done this at the Sheridan 
Furnace, Sheridan, Pa., in making forge or mill iron. 


CHAPTER III. 


CONSTRUCTION OF BLAST FURNACES. 

In the first days of furnace practice the necessity for 
good deep foundations was not realized as at the pres¬ 
ent day. If deep excavations were now to be made 
under many of the old furnaces tons of iron might be 
found. Past experience, dearly bought, has taught 
the furnaceman to provide reliable foundations. In 
some localities the depth required is greater than in 
others, and in some cases piles have to be driven 
before the foundation is started. In the furnace 
shown, Fig. 6, the stone-work illustrated is about five 
feet deep, on top of which a bed of fire-brick about 
five feet deep is laid before the bottom or bed of the 
furnace is reached. Such foundations are costly, but 
it has been found wiser to have capital lying idle in 
them than in lost iron. 

Generally no boiler casing is now used to support 
that portion of the hearth and bosh which incloses the 
tuyeres and water coolers V. This portion of the 
furnace has its fire-brick work supported by means of 
wrought iron bands, six inches wide by one inch thick, 
which encircle this portion at the height of every two 
feet, as seen at S. One idea of not encasing this part 
with solid boiler plates riveted together, as is done 
with the upper part of the furnace as shown, is so as to 
make the placing and attachment of coolers convenient 


CONSTRUCTION OF BLAST FURNACES. 


35 


and permit this portion of the furnace brick-work to be 
exposed to the cooling influence of the atmosphere 

as much as possible. 
It is at this part of 
the bosh and hearth 
that the lining is 
subjected to the 
greatest heat. Fur¬ 
naces are contracted 
at the hearth — 
which constitutes 
all that portion be¬ 
low the tuyere at B, 
mainly to aid the 
blast in reaching 
the center more 
strongly and caus¬ 
ing a more even 
distribution of its 
pressure through¬ 
out the fuel, as well 
.1 as to save the lin¬ 
ing. Such a form 
not only assists the 
blast to reach the 
center, but the 
‘ ‘ batter ’ ’ or bevel of 
such a bosh as shown 
assistsin supporting 
the weight of stock 
charged, thus lessening pressure at the tap hole, per¬ 
mitting the metal to be under better control, with less 
liability to cut the breast as the metal flows out to the 



a 

1 ‘ * 


Stone 


/ 








1 _ -L-A 


fig. 6. 























































































3 6 


METALLURGY OF CAST IRON. 


runner. When a furnace of the size shown is full of 
stock (coke, ore, and lime) the weight bearing down on 
the hearth (when a furnace is working properly) is 
about ioo tons of coke, t6o tons of ore, and 35 tons of 
lime, a total of about 300 tons. Such a weight must 
be very effective in crushing the stock in the reduced 
body of the bosh, so as to greatly retard the penetra¬ 
tion of blast, and is one reason for the high pressure 
found necessary in furnace practice. This also shows 
the necessity for good foundations. 

Decreasing the diameter of the stack from its larger 
portion joining the bosh up to the top, as shown in 
Fig. 10, is mainly to assist in preventing the stock 
from “scaffolding,” which means “ hanging up.” 
(See page 55.) There is no end to the different angles, 
etc., given to furnaces, each style having its advocates. 
We now have Hawden and Howson of Middlesbrough, 
England, who are using a plan of turning present 
forms upside down. We might also mention that 
strictly straight furnaces have been tried, but these, 
it is said, have proved a failure, as a study of these 
pages would lead us to believe. There are over five 
hundred blast furnaces in the United States today and 
many of them differ more or less in their “lines,” 
etc. The .shape or “ lines ” now generally adopted in 
this country for coke furnaces are more in accordance 
with those shown in Fig. 10, in which the hearth is 
about half the diameter of the largest part of the bosh, 
and the throat or top of the stack about two-thirds of 
the bosh’s largest diameter, in a height of about eighty 
feet. 

The construction and principle of furnace tuyeres is 

shown at B, Fig. 6. For the size of furnace shown, 


CONSTRUCTION OF BLAST FURNACES. 


37 


eight tuyeres are evenly divided around the circumfer¬ 
ence and project from 6 to to inches beyond the lining. 
These are for the purpose of aiding the blast to reach' 
the center, and also protecting the lining. A tuyere 
protruding no farther than the face of the lining would 
rapidly cut out the brick-work at that point. These 
furnace tuyeres are made of an alloy chiefly composed 
of copper, so as to approach a bronze metal. This 
class of metal has been found good to prevent the 
melted iron, as it drops down, from adhering to or 
clogging around the tuyeres, which, if it should occur, 
would be very troublesome and liable to cause much 
damage. 

To prevent these tuyeres from melting or burning 
away from exposure to the heat of the fuel and hot 
blast, a constant stream of cold water flows through 
them, going in at H and coming out at P. Often 
through irregular workings, tuyeres may become 
bunged up as in cupola practice, and the method gen¬ 
erally followed to open them is to shut off the blast and 
endeavor to knock a hole through the chilled material, 
after which the hot blast (of about 1,000 degrees heat) 
with its high pressure, which ranges from 6 to 24 
pounds, instead of 6 to 20 ounces, as in cupola practice, 
will assist to cut or burn away the chilled material 
fronting the tuyeres. Should this fail, the blast is 
shut off and the tuyeres are pulled out, thereby leav¬ 
ing a big hole to work through, and by means of 
sledges and steel bars an opening is cut into the fur¬ 
nace and the cold, chilled debris pulled backward out 
of it. In replacing such a tuyere, a large lump of clay 
is pushed forward into the face of the hole to prevent 
the heat melting the tuyere, and then the tuyere is 


38 


METALLURGY OF CAST IRON. 


pressed or knocked inward against the pressure of the 
stock in the furnace until it is in its right place. After 
this is done, any clay that might block up the hole in 
the tuyere to prevent blast to the furnace is broken 
away by means of a bar, and after the water pipes are 
attached, the blast is again put on. The removal or 
insertion of furnace tuyeres is an operation very read¬ 
ily performed, owing to the taper seen in the stationary 
sleeve at T, Fig. 6. This stationary tuyere support is 
cast hollow, of the same metal as the tuyere proper, 
and is kept cool by a flow of water going in at W and 
coming out at F. It is very rare that one of these 
.sleeves has to be removed, as they do not project into 
the furnace, as is the case with the tuyere proper. 

Coolers are very important in furnace construction 
to provide means to assist in lengthening the life of a 
lining. Some furnaces are better provided with cool¬ 
ing appliances than others. In the furnace shown, 
water is admitted to a suspended cast-iron receiver (as 
seen at X), which encircles the furnace, excepting an 
opening of about two feet at the front or breast side of 
the furnace. The cold water is admitted to this 
receiver in its lower division at M, and after having 
done its work it flows into the upper division and is 
carried off through the waste pipe N. The pipes 
Y are those which admit the cold water to the 
coolers, and P those-returning the heated water to the 
waste receiver. At V V V are seen some of the many 
coolers whicn are built in the furnace lining to preserve 
its life. In the furnace shown these are placed in 
layers about thirty inches apart in height, and has 
about two feet of space between them. Some furnaces 
have them built much closer than this, both in height 


CONSTRUCTION OF BLAST FURNACES. 


39 


and circumference. There are various plans of coolers 

used with furnaces. The coolers here illustrated are 

made of cast-iron about three inches thick by two feet 

square, and each has three independent coils of one 
» 

and one-half inch pipe cast in it, so arranged that 
should the front coil be attacked by the heat as it 
burns out the lining, it .can be shut off, and the inner 
coils be made operative independently or as a whole. 
Some furnaces have these coolers made of bronze, cast 
hollow. It is very seldom trouble is experienced with 
the coolers shown, and if any should occur arrange¬ 
ments permit their being taken out and replaced. At 
L is seen a two-inch pipe, perforated with one-eighth 
inch holes about two inches apart, which encircles the 
furnace and keeps a constant stream of cool water run¬ 
ning down the plate I which supports the hearth 
portion of the furnace. This water runs down on the 
outer surface of the plate to a reservoir at R, and 
which can be filled up with water to a height of about 
three feet, to protect the lower portion of the hearth 
with a heavy body of water. A valve is so arranged 
in the reservoir R that any height of water can be 
maintained in it. It is no unusual occurrence for the 
metal to break out at this portion of a furnace, result¬ 
ing in much injury to life and property. The furnace- 
man’s lot is by no means one any need envy, for he 
shares very fairly the troubles and dangers he has who 
“ meddles with hot iron.” 


CHAPTER IV. 


LINING AND 'DRYING OF FURNACES. 

Methods of lining a furnace and the shape of the 
bricks have as much to do with the life of the lining as 
other qualities defined in this chapter. It is very 
expensive to line a modern furnace, and when com¬ 
pleted it should give, at least, a continuous service of 
two years with hard ores and three years with soft 
ores, and this length of service may often be doubled. 
When it is stated that 450 tons of fire-brick and 60 of 
fire-clay, or a heavily laden train of about twenty-five 
cars of material, are necessary to line such a furnace 
as seen in Fig. 10, the magnitude of such a job, as 
compared with lining even our largest cupolas, can be 
readily perceived. Bricks for a furnace are largely 
made to order, so as to neatly fit its curves, slant, or 
circle which the form of the shell or inside of the 
lining, etc., may exact. This is done so as to have 
all joints fit as closely as possible without cutting 
bricks or filling in the clay. Bricks of a softer quality 
than those used for the stack portion of the furnace are 
desired for the hearth and bosh, as the former are 
exposed to greater destruction from friction, while 
those in the hearth and bosh portion are chiefly sub¬ 
jected to the action of heat. Such a quality, if used in 
the stack portion, though its composition is best able 
to withstand the heat, would soon wear away by the 


LINING AND DRYING OF FURNACES. 4 ) 

constant friction of the stock, so that better service is 
found by sacrificing the heat qualities to those best 
calculated to withstand friction for stack linings. 

In laying bricks, a thin grouting of the best fire-clay, 
without mixture of sand, is used. The clay is mixed 
of such consistency that a brick, if dipped into it, 
would, upon being lifted out, have a coating of about 
one-eighth of an inch adhere to it. To make a bed of 
clay for the brick to be laid in, a dipper is used to pour 
the clay upon the surface of the last course, laid to a 
thickness of about one-fourth of an inch. The bricks 
are then slid on soft clay up to each other so as to 
imbed themselves firmly, and closely force the clay 
between all joints, after which a hammer is used to 
crowd the -joints still more closely together or bed 
the bricks more firmly. In order to obtain a true 
circle when lining the hearth, bosh, and stack of a 
furnace, a plumb bob-line is dropped from the top to 
obtain a center for a “spindle” with a “sweep” 
attached, which is to be carried up as the work pro¬ 
gresses, just as a loam moulder would build a large 
cylinder mould. The time usually occupied in lining 
such a furnace as shown in Fig. io, employing four 
masons and twelve helpers, is about thirty days. 
The work of lining a furnace is considered a specialty, 
and the leading men in such work are carefully 
selected from those having the greatest experience in 
this line, as any faulty construction can easily result 
in a very short run of a furnace, thus causing a great 
expense in “ blowing out ” to remedy the evil. 

Space for expansion of fire=brick, as illustrated at 
K, Fig. 6, and both sides of Fig. io, page 49, is a 
practice now followed in lining furnaces. This space 


42 


METALLURGY OF CAST IRON. 


ranges from three to four inches in width, and in 
length from the bosh portion up to the top of the 
stack, as shown, the hearth being built solid, as seen in 
the sketch. A material now extensively used for filling 
this expansion space, K, is the slag of a furnace, after 
being granulated by the action of water. A loamy 
sand was at one time used, but it packs too firmly. 
Then, again, a coarse class of sharp sand has been 
used, but the slag as above prepared has been found 
the best. Experience has proven the necessity of such 
a system, as several furnaces have had their shells 
ruptured by the expansive force of fire-bricks when 
not permitted room to swell from the effects of the 
heat. Not only have furnaces provided for this lateral 
expansion, but also for longitudinal strains as well, as 
such action has been known to press the brick-work, 
bell, hopper, and charging platform upward from 
three to four inches above the top of the shell, or its 
original level. All the iron work at the top of a fur¬ 
nace is constructed independent of the shell, so as to 
liberate it from all strain when longitudinal expansion 
takes place. 

Drying a furnace becomes necessary before it is 
charged for “blowing in.” There are several meth¬ 
ods of doing this. One is by building a fire inside the 
furnace; another by constructing a fire-place outside, 
at the breast portion, and letting the heat from the 
same pass into the furnace; still another by the admis¬ 
sion of natural gas, or the gas from the ovens of 
another furnace, should two or more furnaces be near 
each other. The objection to building a fire inside a 
furnace is that the dirt and ash which it creates 
requires considerable labor to clean out, and requires 


LINING AND DRYING OP' FURNACES. 


43 


more fuel than by any other plan, but is quicker in its 
action of drying. After a fire has been well started, 
all holes around the furnace and the top, with the 
exception of a “bleeder” H, Fig. 13, page 57, of 
about twelve inches diameter, are closed, the “ bleeder ” 
being left open to create draft. The time taken to 
dry a furnace ranges from one to four weeks. 

The life of a furnace lining not only depends upon 
qualities described in preceding paragraphs, but also 
upon the manner in which a furnace is worked. Those 
that are driven hard by high blast pressures, to get 
the greatest possible output of iron, have not nearly 
the life of those driven more mildly. America is noted 
for fast driving to attain greatest output. For this 
reason if furnaces run steadily for five years in 
our country they are doing very excellent work, 
whereas in Europe furnaces have run steadily for ten 
to fifteen years; although they are commencing to 
drive them faster than formerly. 

One factor of great protection to linings exists in 
the formation of a kind of graphite or carbonaceous 
concrete which accumulates on the face of the lining; 
this comes from the kish, slag, and carbon refuse gener¬ 
ated in the furnace, which may be found two to twelve 
inches thick on the lining, the greatest thickness being 
found in the hearth or lower body of a furnace. 

The factors which destroy the life of furnace linings 
are defined under four heads by Fritz W. Lurmann in 
the Journal of the Iron and Steel Institute, 1878, Vol. 
I., page 200, as follows: 

“ 1. The actual wear due to contact with the descending 
charge. This is relatively unimportant. 2. The actions of the 
alkaline cyanides and other substances present in the furnace 


44 


METALLURGY OF CAST IRON. 


gases which, though probably important, produce an effect the 
amount of which is at present not accurately determined. 3. 
The action of sodium chloride or other alkaline substances con¬ 
tained in coke; this is probably one of the most important causes 
of wear, as at a high temperature salt is decomposed by silica, 
and a fusible silicate is obtained. 4. The flaking of the bricks 
due to decomposition of carbon from carbon monoxide around 
any iron particles reduced from impurities in the original bricks. ’ ’ 

The best grades of fire-brick are necessary in lining 

furnaces. Absolute fire-proof bricks, it may be said, 
are not obtainable. Several kinds of material have 
been tried in an effort to secure a lining for furnaces 
that would exceed the life of the general character of 
fire-bricks used. We have what are called silica, car¬ 
bon, ganister, coke, magnesia, and asbestos bricks, all 
of which have been experimented with, and, to some 
degree, all have advocates of their utility in certain 
lines of work. Carbon bricks, it is claimed, have worn 
well, made of fine coke (poor in ash), or charcoal mixed 
with clay with tar as a binder. If such bricks contain 
more than 70 per cent of silica, as used for high 
temperatures, they are generally very friable and 
( disintegrate with the least friction, so that bricks of 
this character would be suitable only for the lower 
body of a furnace. As clay is chiefly silicate of 
alumina, which is also a good substance to resist high 
temperatures, it works well as a binder with silica in 
making fire-bricks. The other substances in clay are 
iron oxide, lime, magnesia, potash and soda, which, to 
some degree, decrease the durability of fire-bricks. 
As fire-bricks come to the furnace or foundry they are 
often composed of about equal parts of silica and 
alumina. Bricks should contain silica or alumina in 
proportion to the amount of heat or friction they are 


LINING AND DRYING OF FURNACES. 


45 


required to withstand. The life of fire-brick depends 
upon the purity of these ingredients. The silica 
should be pure quartz or anhydrous silica, and not 
uncalcined or raw rock for a substitute as is often 
practiced by some. It can be readily seen that one 
kind of fire-brick may give excellent service with one 
character of work and very poor for others. 


CHAPTER V. 


! 


OPERATING BLAST FURNACES AND RE¬ 
DUCTION OF ORES. 

The amount of stock that passes through a furnace 
the size of that seen in Fig. io, page 49, every twenty- 
four hours is about 280 tons of ore, 190 tons of coke, 
and 60 tons of limestone, a total of 530 tons. In filling 
a furnace by hand labor, two gangs of. men are always 



employed, one at the top, and the other on the ground 
floor load the buggies and wheel them to the 
elevator, which ascends a distance of 70 to 100 feet in 
about twenty seconds. There being two cages to the 
elevator, an empty one is returned as the loaded one 



OPERATING BLAST FURNACES. 


47 



FI G. 8.— HOISTING APPARATUS OP' A MODERN FURNACE — LABOR ALL 

ACCOMPLISHED BY MACHINERY. 

of the bell, on the charging platform, for creating a 
draught to carry off the escaping gases. Improve¬ 
ments have been made whereby all stock is carried up 
and dumped by machinery into the hopper, so that 
there is no need for men working on a furnace as “top 


ascends. The buggies used hold about 800 pounds of 
ore and of coke 450 pounds. The men charging the 
furnace are called “ top fillers ” and those loading the 
buggies ‘ ‘ bottom fillers. ’ ’ The work is thoroughly 
systematized, each man knowing his part. Top fillers 
hold a somewhat hazardous position, as it is not uncom¬ 
mon for men to be “.gased ” by the fumes escaping at 
the bell and hopper of a furnace. Some furnaces 
suspend a sheet iron stack about ten feet over the top 




















































































FIG. Q.—ENLARGED VIEW OF MODERN BLAST FURNACE. 







OPERATING BLAST FURNACES. 


fillers. ’ ’ A view of this 
more modern plan of 
charging a furnace is 
shown in Figs. 7 and 8, 
and which are illustra¬ 
tions used by Mr. Walter 
Kennedy in the A merican 
Manufacturer , January 
3,1901. We also present 
cut Fig. 9, which was 
originally shown in the 
Journal of the Associa¬ 
tion of Engineering So¬ 
cieties, January, 1901. 

In charging a furnace, 
the coke, limestone, and 
ore are generally dumped 
in the order mentioned 
and dropped independ¬ 
ently of each other in the 
hopper H, Fig. 10. Af¬ 
ter the completion of each 
charge, the bell B is then 
lowered as indicated, and 
the material falls into the 
furnace shown, about as 
illustrated at the mound 
M M. After the delivery 
of the charge, the bell 
returns to its position, 
ready to receive the next 
supply of stock. There 
are several ways of oper- 


49 


Weight 



A FURNACE. 





























































































































































































































5 ° 


METALLURGY OF CAST IRON. 



FIG. II. 


ating the bell, but 
the method used with 
the furnace shown is 
that of moving the 
beam S up and down 
by means of a piston 
D, which can be 
operated by steam or 
the blast pressure. 
The bell must be 
hung true, since, if 
one side should swing 
lower than the other, when the stock is admitted to 
the furnace, the charge would lodge unevenly and 
have a tendency to cause scaffolding and other evil 
results, similar to uneven charging of stock in a cupola. 

Where the bell and hopper are used for charging 
stock, the angle and diameter of each, as compared 
with the diameter of the furnace at its throat or stock 
line, have all to do with the form and position which 
stock assumes when dropped into it. The angle of the 
hopper influences 
that of the bell in de- \ ffo PP er 

termining the distri- 
bution and position 
of coarse and fine ma¬ 
terial, also the forma¬ 
tion of the irregulari¬ 
ties in mounds which 
a charge may as¬ 
sume, after being 
dropped by a bell in¬ 
to a furnace. It is 


hA. 



FIG. 12. 








































































































OPERATING BLAST FURNACES. 


5T 

generally conceded that the small bell, as in Fig. n, 
sends the coarse material to the outside circle, while 
the larger bell, Fig. 12, sends it to the inner circle, 
and the coarse material may descend faster than the 
fine stock. Furnacemen are now largely using small 
bells. 

The action of stock in passing down through a fur¬ 
nace should attain, if possible, an occasional shifting 
movement, so as to retard the formation of any solid 
mass of the stock. This is best achieved in a taper 
stack, as the stock in passing downward should assume 
an action somewhat similar to that illustrated in the 
various levels, A, B, C, D, E, and F, seen in Fig. 10, 
page 49. When stock is dropped by a bell, such as in 
the size of the furnace shown, it is generally, if all is 
working well, distributed in a form somewhat like that 
in the mounds M M, seen at the level A, which is called 
the “ stock line,” and is generally ten feet below the 
level of the bell. The stock in Settling down to fill 
the increasing diameter of a tapering stack must have 
a spreading out or leveling action taking place, or in 
other words, the outside would descend faster than the 
inside stock. It seems reasonable that the tendency 
of the stock in settling would be to have the angles 
constantly leveling themselves somewhat after the 
idea illustrated at the various strata B, C, D, and E, 
Fig. 10, until it has reached the bosh at F, when reac¬ 
tion would take place and the stock in descending would 
be retarded by the walls of decreasing diameter and 
cause the center portion to travel faster than the side, 
until at the last stratum, I, the center stock would 
have traveled ahead of the side stock as shown at R. 
Before this point is reached, however, the reaction 


52 


METALLURGY OF CAST IRON. 


(which changes the oxide of iron in the ore to metallic 
iron, and carbonizes it to form cast iron) has taken 
place and all the stock is liquefied, gases have escaped, 
and what passes to the point Y is some remaining fuel 
which replenishes the bed over the melted iron and 
slag. The total length of line at the different levels, 
B, C, D, and B, is the same. In cupola practice, 
foundrymen have the advantage over furnacemen in 
being able to observe the action of the stock until it 
has reached the “ melting point.” In observing stock 
settle at the last charge in a straight cupola, when all 
is working well, little or no change is noticed in the 
position of the material, and this is generally so true 
that the founder knows that whatever way stock is 
delivered into a cupola it will generally be found so 
situated when it reaches the “ melting point.” For 
this reason founders often have experience with 
44 bunged mp ” cupolas or iron dumped at “bottom- 
drop,” which could not be melted owing to fuel or iron 
not having been charged evenly. Often stock reaches 
the melting point with fuel mostly on one side and 
iron on the other through carelessness in charging in 
that manner. 

In the descent of the stock, coke, limestone, and ore, 
all moisture is driven off, the thoroughly dry and 
heated ore now comes in the zone of reduction, where 
the oxygen is taken from it, and changed from oxide 
of iron to metallic iron, during which process the iron 
takes up carbon from the fuel, and, melting in the zone 
of fusion, finally arrives at the bottom in form to be 
tapped out. The non-metallic or earthy matter, in 
separating from the reduced iron, unites with the lime 
or flux and, being lighter than iron, floats on its surface 


Operating blast furnaces. 


53 


and is tapped off as slag- through the slag hole T, Fig. 
io , page 49, while the iron is delivered at the tap hole 
X. The amount of fuel and limestone necessary, de¬ 
pends upon the nature of the ore charged and the grade 
of iron desired. All material charged into a furnace 
passes off either as a liquid or as a gas. The gas which 
comes off at the top is made to pass through the down 
comer into the ovens and burned there. There the 
blast is heated while passing to the furnace. The 
liquid products which pass off are iron and slag, both 
formed at a point ranging from a level with the tuyeres 
to a height of about four feet above them, a portion 
generally called the “ melting zone,” or bosh, the hot¬ 
test part of a furnace. 

If ore is not properly reduced a percentage of its iron 
may pass off with the slag, the reason for this being 
that it is not thoroughly extracted from the ore and 
non-metallic matter. This is generally due to an 
insufficient amount of fuel, or decrease in temperature 
from other causes. Moreover, too small an amount of 
silicon is reduced at the same time from the fuel and 
ore, and consequently the iron obtained is smaller in 
amount and silicon contents and richer in sulphur. 
The furnace is working cold, or ‘‘off,” and a greater 
per cent of fuel may make it work better. 

Sulphur in iron is generally largely obtained from 
the fuel in a furnace. Iron from the ore, as well as 
the lime in the flux absorbs sulphur. Which of these 
two elements, in the process of reducing the ore, will 
absorb the greater percentage of sulphur from the fuel 
depends upon the degree of heat obtained. Lime has 
a great affinity for sulphur, and if the slag is made 
thin and hot it can counteract the absorbing power of 


54 


METALLURGY OF CAST IRON. 


the iron and take much of the sulphur itself. If the 
furnace is working - cold so as not to properly fuse the 
limestone, then the iron will absorb and retain higher 
sulphur; and hence the greater sulphur found in the iron 
coming from a coldworking furnace, which often 
results in giving a hard or “ white iron.” The way 
high silicon and low sulphur iron, or No. i pig iron, is 
generally obtained is by having a hot furnace, well but 
not excessively fluxed with lime. To make high silicon 
and high sulphur iron, as is often obtained, it is neces¬ 
sary to have a hot furnace poorly fluxed with lime. A 
cold furnace gives a thick, bad slag, the same as a cold 
cupola retards good fluxing or slagging out. A good 
working furnace sends the most silicon into the pig 
and sulphur into the slag; a poor working furnace 
reverses these conditions. 


CHAPTER VI. 


CAUSE AND EVILS OF SCAFFOLDING AND 
SLIPS IN A FURNACE. 

The factors causing the greatest irregularity in the 

working of a furnace are scaffolding and slips. This 
means that a portion of the stock will hang at one 
point for a period and then suddenly becoming loos¬ 
ened, will slip for a distance and reach material filling 
the bottom or hearth of a furnace. There are four 
factors effecting the hanging of stocks and slips, which 
are evils all furnacemen aim to overcome. The first 
of these is the lines of the furnaces, the second the man¬ 
ner in which the stock is delivered to the furnace, the 
third the quality or nature of the ore and fuel used, and 
the fourth the state of the temperature of the blast and 
atmosphere causing a furnace to work cold or hot. A 
few years ago experts said that the Messabi ores could 
not be smelted in a furnace, owing to their being so fine 
and loamy. But the large percentage of iron which 
they contain, their low phosphorus, (which makes it a 
good ore for Bessemer,) and low sulphur, three very 
desirable elements, combined with low cost, caused 
furnacemen to try it and persevere in its use, until 
to-day it is a large percentage of the ores charged into 
many furnaces. Nevertheless, furnacemen find much 
trouble from slips and wastage of this ore in the form 
of fine dust being carried out with the gases through 


56 


METALLURGY OF CAST IRON. 


the “down-comers.” There is much study being 
given in hopes to devise methods to overcome these 
difficulties. To help matters, a few have taken out 
their old bells and replaced them with smaller ones, 
and they report a very commendable improvement in 
preventing slips when using Messabi ores. 

The reason for stock scaffolding in a furnace is often 
found in the irregularity of the lining. The constant 
friction of the stock in working downward cuts cavi¬ 
ties into the lining, often forming regular shelves 
upon which the stock can easily hang up. The longer 
a furnace runs, the more favorable conditions become 
to scaffolding, and when it -is stated that ore is a sub¬ 
stance which becomes gummy and swollen before it is 
reduced to a fluid state, one can readily perceive why 
such trouble may be expected in a furnace, causing an 
irregularity in the product, and at times disarranging 
all calculations of the furnaceinan by producing an 
undesired character of iron. When furnacemen 
experience trouble with scaffolding, etc., not due to a 
hot furnace, as described in Chapter X., page 75, they 
often resort to the use of more fuel than when all is 
working well. The additional percentage of fuel 
causes a greater heat, making the stock more plastic, 
and causing it to give way more easily from the walls 
of a furnace. It generally takes from five to ten 
hours for stock to work down from the top to be 
tapped out as iron. 

A slip in a furnace often means the falling of from 
twenty-five to two hundred tons of stock from a height 
of one to fifteen feet. The contemplation of this tak¬ 
ing place within a furnace filled with combustible 
gases, heated stock, and liquid metal should enable 


CAUSE AND EVILS OF SCAFFOLDING, ETC. 


57 


any one to form some conception of the damage that 
could be done, and the reason all hands around a fur¬ 
nace have good cause to fear a slip. The scaffolding 
of a furnace can prove so disastrous as to disable or 

make unsafe its work¬ 
ing parts. The au¬ 
thor has seen a slip 
cause such an explo¬ 
sion as to lift the bell 
and hopper F. and K, 
Fig. 13, throwing 
them out almost on 
top of the furnace plat¬ 
form, and straining it 
to such an extent that 
it was a question 
whether it was safe to 
rely on the furnace 
shell; and he has-heard 
of a bell and hopper 
being” thrown about 
twenty feet from a 
furnace. Plans have 
been adopted to re¬ 
lieve sudden gas pres¬ 
sure, some of which 
are working very satis- 
FIG> I3> factorily, especially the 

system used at the Alice Furnace, Sharpsville, Pa., 
designed and patented by Mr. P. C. Reed, the 
furnace superintendent, and shown in Fig. 13. The 
idea is to build four large openings equally divided 
around the circumference within a few feet of the 






































58 


METALLURGY OF CAST IRON. 


top of the stack. These are connected with flues 
branching upward about eight feet high, and closed 
by means of valves hung on pivots, as seen at H H, 
and so regulated by weight that they will open of 
themselves when any excess of pressure is created 
in the furnace. This improvement is a step forward in 
furnace practice which diminishes the risks of accidents 
and loss of life, but it still remains to better guard 
against the evils of scaffolding or the slipping of stock 
so detrimental to successful furnacing, often requiring 
several days after a slip to get a furnace back again to 
working satisfactorily and give a fair uniform grade 
of iron. 


CHAPTER VII. 


COMPOSITION AND UTILITY OF FLUXES. 

The object of fluxing furnaces and cupolas is to give 
fluidity to the non-metallic residuum of the iron ore 
and the ash of the fuel, to carry it out of the furnace 
or cupola in the form of slag. While this is an impor¬ 
tant function, there are certain chemical compositions 
that can exist in fluxes which best assist in obtaining 
desired results, similar as there are certain chemical 
constituents necessary in ores to obtain the brands or 
grades of iron desired. All fluxes should be as free of 
earthy matter as possible, since such retards their 
action. High silica and sulphur are likewise objection¬ 
able. The element most essential in a flux to aid the 
creation of slag is lime. This is found in various sub¬ 
stances,. as in marble, spalls, oyster and clam shells, 
limestone, chalk, dolomite, calc-spar, fluor-spar, and 
felspar. 

Magnesia largely serves the same end as lime, but 

less of it is required. About two of the former is 
sufficient, where three of the latter would be required. 
Dolomite contains more magnesia than any other class 
of limestone, and is often called magnesia limestone 
and generally contains about 55 per cent of calcium 
carbonate and 40 per cent of magnesium carbonate, 
with the rest largely silica, oxide of iron, and alumina. 


6o 


METALLURGY OF CAST IRON. 


Dolomite is now being used in the making of high 
silicon and other irons, but it is said it is not as effec¬ 
tive in lowering sulphur in iron as limestone where 
sulphur is troublesome. 

The more silica a flux contains the greater fuel or 
higher temperature required to fuse it and the less its 
value as a flux, for the reason that more lime is 
required to unite with the silica to make a good slag, 
and the more silicious the ore the more lime generally 
required to flux it. It has been known to require 
more lime than there was ore charged in order to flux 
the high silica which the ore contained. Silica as 
found in slag is not only derived from the fuel and 
ore, but also from the scale and sand of any iron which 
may be charged into a furnace or cupola, and from the 
oxidation of the silicon in iron during the heat. It is 
to be remembered that the more lime a flux contains, 
the better it serves the end of creating slag to affiliate 
with the earthy matter and debris formed in a furnace 
or cupola, and also the more silica or lime there is in 
a furnace or cupola, the more fuel required to smelt or 
melt the iron. Alumina is also pronounced in its 
effects upon the decrease or increase of the fluidity of 
the slag. As a general thing, the more alumina the 
higher the temperature required to fuse the flux in 
order to make a good liquid slag. 

The following Table io is a compilation of fluxes 
which the author has used with good results, and will 
serve to illustrate the physical as well as the chemical 
properties, and will also show that a flux which might 
work well in a furnace can often be well utilized in 
cupola practice: 


COMPOSITION AND UTILITY OF FLUXES. 


6l 


TABLE IO. 



No. 1. 

No. 2. 

No. 3. 

Silica. 

3 -oa 

1.98 

•54 


Iron Oxide. 

.92 

• GO 

.12 


Alumina. 

1-25 

.90 

•36 


Phosphorus. 

.020 

•°37 




Sulphur.. 

.020 






Carbonate of Lime. 

92.10 

82.85 

98.73 

Carbonate of Magnesia. 

1.26 

13.04 


Lime Oxide. 

51-57 

46.41 

53 - 3 2 


Magnesium Oxide . 

1.63 

17.23 





The physical character of No. i is very hard and of a 
dark color, and is a grade of limestone largely used 
for blast furnaces. It is obtained near New Castle, 
Pa. No. 2 is of a much softer quality than No. i and 
also more white and clear in its color. It is known as 
Kelly Island limestone and is mined at Marblehead 
and Lakeside, O. No. 3 is softer and purer in color 
than either Nos. 1 or 2 and has something of a checked 
marble cast. It is obtained from the Benson Mines, 
New York, and instead of being called limestone as 
are the first two shown, it is defined as calcite by the 
shippers. It will be noticed that Nos. 2 and 3 have 
no sulphur. For many classes of work this is prefer¬ 
able to No. 1 As sulphur in limestone is similar in 
its effect to sulphur in fuel, it largely passes into the 
iron and raises its sulphur contents. For cupola work 
preference, as far as labor is concerned, would be 
given to Nos. 2 and 3 owing to these being more 
friable than No. 1, but the furnace limestone No. 1 is 




























































62 


METALLURGY OF CAST IRON. 


less expensive. All the above fluxes are used just as 
they are mined, being- in no way burned or roasted — 
a treatment necessary to some grades of limestone — 
and will benefit, it is claimed, almost any flux of a 
rock character. When this is done with limestone it 
gives us quicklime, a form that requires less weight 
when charged than limestone. The action of burning 
or roasting causes the limestone to become friable, so 
as to largely eliminate its carbonic acid and other 
volatile matter and generally make a limestone more 
ready to unite with the impurities. W T hile such treat¬ 
ment of limestone would naturally be expected to be 
economical, it has not proven so in all cases. When 
the fuel required to roast it is taken into consideration 
with that which may be saved in converting it into 
slag in the smelting of iron, there is considerable 
difference of opinion in regard to the question of 
economy for furnace practice. 


CHAPTER VIII. 


FLUXING AND SLAGGING OUT FUR¬ 
NACES 

The percentage of ore and fuel which must be carried 
off by the slag in making iron consists of ten to thirty 
per cent of the former and ten to fifteen per cent of 
the latter. A portion of this extraneous matter is 
basic, the rest acid. The chemical affinity thus exist¬ 
ing is such that, when this material is subjected to high 
heat, union is effected, the whole passing into a fluid 
state. Generally the 'percentage of basic in, the refuse 
is not sufficient in its action on the acid matter to 
reduce it to such a fluid state that it will flow freely, 
or properly extract all extraneous matter from the ore. 
To remedy this defect, limestone or other flux is gen¬ 
erally added to all charges of ore going to a furnace. 
While the lime, etc., assists in fluxing the refuse to 
the state of fluidity required, it also affects the quality 
of the iron produced as described in pages 53 and 54. 

The grade of iron which is to come from a furnace 
can generally be foretold by the nature of the slag 
tapped or flushed before the iron is tapped. If a lump 
of solid slag, when broken, presents a black color, 
very dense in its composition, it is generally supposed 
to denote the production of iron very low in silicon and 
high in sulphur, with high iron in the slag. If slag is 
of a light or gray color and its fracture presents a porous 


64 


METALLURGY OF CAST IRON. 


composition, it is generally an indication of a produc¬ 
tion of iron which will be well up in silicon and low in 
sulphur, with low iron in the slag. Degrees in color 
and solidity of the slag between the two extremes may 
vary according to the difference found in the grade of 
the iron. Foundry irons generally produce a slag 
more silicious or “ stony ” than Bessemer irons. The 
use of high manganese or manganiferous ores gener¬ 
ally produces either a green or brown slag. A green, 
glassy slag, from such ores, indicates that the furnace 
is working well, but a brown slag denotes the reverse. 
These grades of slag are generally produced in the 
making of spiegeleisen and high manganese iron. 

The slag called ** scouring cinder” is generally the 
worst slag which comes from a furnace. It is of a 
reddish brown color and is chiefly caused by a slip or 
some bad working of a furnace, causing ore to pass 
down to the fusion zone in an unreduced state. This 
class of slag is very cutting to the lower lining of a 
furnace, owing to its containing so much oxide of iron 
and being very basic, a combination most effective in 
dissolving the silica in the bricks forming the lining. 
Some furnacemen are having their slags analyzed at 
every cast, as a guide in regulating their furnace. 
This proves very satisfactory in assuring a furnaceman 
as to the character of the iron he may expect, or 
whether any changes are taking place which might 
call for prompt attention in making alterations in the 
manner of charging or working of his furnace. Some 
expert furnacemen can greatly vary the grain of an 
iron by methods of fluxing or, in other words, cause 
like percentages of silicon, sulphur, and carbon to 
make some casts open-grained and others close-grained 
iron. This shows still further why the appearance of 
fractures in pig iron is so often deceptive. 


FLUXING AND SLAGGING OUT FURNACES. 


65 


To afford some knowledge of the chemical relation 

which slags bear to the iron produced, the analyses in 
Tables 11, 12, and 13, obtained by the author, are 
presented: 


TABLE II — ANALYSIS OF FOUNDRY IRON. 


Silicon. 

Sulphur. 

Manganese. 

Phosphorus. 

2.09 

.013 

•25 

.769 


TABLE 12 — ANALYSIS OF SLAG. 


Silica. 

Alumina. 

Lime. 

Manganese. 

Magnesia. 

Iron. 

Total. 

33 -08 

19-74 

44-74 

.11 

1.44 

.40 

99-51 


Table 13 is slag selected from the compilations of 
different authors to present a knowledge of the char¬ 
acter of slag produced from different ores and classes 
of fuel. The first and second columns are slags pro¬ 
duced from raw coal smelting at Dowlais, Wales, 
presented by Riley. The first column is a slag from 
gray iron and the second from white iron. The third 
column is a slag from coke with Cleveland ores making 
gray iron, by Bell. The fourth is from anthracite, 
making gray forge iron, at Bloomington, N. J., and 
the fifth is from charcoal iron made at Josberg, 
Sweden, by Sjogren: 


TABLE 13 — ANALYSES OF BLAST FURNACE SLAGS FROM DIFFERENT 

ORES AND FUELS. 



1 

2 

3 

4 

5 

Silica. 

Alumina./.... 

Lime.. 

Protoxide of Iron. 

Manganese. 

Magnesia. 

Sulphide of Calcium. 

38.48 

15-13 

32.82 

0.76 

1.62 

7-44 

2.22 

1.92 

0.15 

43 -o 7 

14.85 

28.92 

2 53 
1-37 
5-87 
1.90 
1.84 

27.68 

22.28 

40 12 
0.80 
0.20 
7.27 
2.00 

42.17 

13-59 

33-02 

1.28 

0.27 

8.31 

0.64 

61.06 

5-38 

19.81 

3-29 

2.63 

7.12 





rnospnoru. auu. 






100.54 

100.35 

100.35 

99- 2 3 

99.29 































































66 


METALLURGY OF CAST IRON. 


The percentage of silica slag contains, sometimes as 
high as 60.00, as seen in Table 13, shows us ways in 
which silicon can be carried off or reduced in smelting 
or remelting iron. The weight of slag produced is 
dependent upon the character of the ore, fuel, and flux 
used. The furnace can produce a greater weight of 
slag than iron, but, as a rule, 600 to 1,000 pounds of 
slag are made to the ton of iron. The richer the ore, 
the less slag in the normal working of a furnace. The 
slag created at a furnace must be disposed of. We 
find machinery utilized in this work, as in other manipu¬ 
lations of furnace practice. Some have it conveyed 
in large receptacles, which are hauled by power to cars 
or dumping ground. When overturned, they release 
the slag in a molten form, or solidified state. Another 
plan is to let it run from the spout Y, Fig. 18, page 90, 
to furrows in the ground, which may be run for a 
length of two or three hundred feet, often covering an 
acre of ground. This slag is pulled out of its furrows 
by hooks in the hands of men before it has thoroughly 
solidified. In removing the slag from the ground it is 
shoveled into carts and teamed to the dump, or thrown 
on cars to be transported and used for railroad ballast, 
or for making roadways. Then again, the slag is run 
into a deep pit, after being granulated by a stream of 
water issuing from a pipe in the trough, which strikes 
the slag as it leaves the trough to drop into the pit. 
This granulated slag is hoisted by a steam shovel and 
dumped into cars, doing away with much hand labor. 
This plan is used at the Alice Furnace, Sharpsville, 
Pa., and Ella Furnace at West Middlesex, Pa., after 
plans designed by Mr. E. H. Williams, the general 
manager. The pit used is about twenty feet square by 


FLUXING AND SLAGGING OUT FURNACES. 67 

twenty feet deep, and all the slag made by the furnace 
is dumped by the steam shovel into cars and used by 
some railroads as ballast, and filling up dumps. 

Mineral wool is made from slag by remelting fur¬ 
nace slag in a cupola, under patents obtained by Wood 
Brothers, of Wheatland, Pa. The process consists of 
charging the slag in -connection with coke after the 
plan of melting iron. As the slag flows out it is met 
at the outlet of the slag-hole by three flat streams of 
steam, which divide its particles into threads of mineral 
wool and blow the same into a large building about 
one hundred feet long and thirty feet wide, pre¬ 
pared for its reception. Variations in the character of 
slags create different grades of wool, which is sorted 
and packed according to its commercial value. The 
wool may often be of such a coarse, poor quality as to 
be unfit for commercial purposes. There is always a 
difference in the density of the wool at every cast. 
The lightest is deposited or blown farthest from the 
cupola and the heaviest grade nearest to the cupola. 
The wool is chiefly used as a non-conductor of fire, 
packed between the walls and floor spaces of fire-proof 
buildings, etc. This mineral wool resembles in char¬ 
acter that which the founder finds coming from cupolas 
which are slagged out. 

For every tap of iron made from a furnace, there 
are generally two taps for slag. This is termed “ flush¬ 
ing a furnace.” In the furnace shown, Fig. 6, page 
34, the number of taps for iron during twenty-four 
hours generally ranges from four to five. In about 
the middle of every tap the furnace is “ flushed ” and 
then again about twenty minutes before tapping for 
iron. The old way of tapping to flush a furnace is 


68 


METALLURGY OF CAST IRON. 


simply by having a hole in the lining through to the 
inside of the furnace, and after the same is tapped to 
plug it with clay, on the same principle generally 
followed in tapping a slag-hole in cupola work. The 
modern plan for making and operating a flushing-hole 
is that shown in Figs. 18 and 19, pages 90 and 93. At 
N is a bronze casting into which is inserted what is 
termed a “ monkey tuyere,” P, both of which are kept 
cool by a flow of water passing through them. In tap¬ 
ping a slag-hole to flush a furnace the projection H is 
slightly jarred by means of a sledge which loosens the 
stopper R. After this has been removed, as shown 
by A, Fig. 18, a steel pointed bar is then used to cut 
through the inch or two of chilled slag, which has 
generally been formed in front of the plug F. This 
chilled slag is generally removed with ease, permitting 
the cinder to flow out. The time generally taken for 
the slag to be all flushed out ranges from five to seven 
minutes. It is not long after the slag has commenced 
to run before the blast makes its appearance, blowing 
gas and sparks of cinder for from twenty to thirty feet 
from the flushing-hole. As soon as the flushing is 
completed, the iron plug stopper R is quickly thrust 
into the hole, which at once chills the slag around it, 
and stops the leakage of blast. The stopper R is a 
wrought iron bar with a cast iron cone cast on the rod 
which forms the plug as shown. The difference 
between this method of tapping a flushing-hole and 
the old plan used is simply in the convenience, and 
the use of clay is avoided. The iron and slag-holes of 
a furnace are sometimes lowered or raised from their 
original positions by reason of a furnace filling up with 
chilled iron, but if this can be avoided by tapping the 


FLUXING AND SLAGGING OUT FURNACES. 69 

iron, as well as the cinders, out of the slag-holes, as 
described in the middle of the chapter, it is often done 
in preference to changing the position of the iron and 
slag-hole, as above described. Any one desiring 
further information on fluxing or slagging in its rela¬ 
tion to cupola work is referred to “ American Foundry 
Practice,” page 331, and the “ Moulder’s Text-Book,” 
page 310. 


CHAPTER IX. 


COLD AND HOT BLAST VS. COMBUSTION. 

There are four kinds of blast. The first is called 
“cold blast,” the second “warm blast,” the third 
“hot blast,” and the fourth “superheated blast.” 
Cold blast is generally employed by founders in 
remelting metals in a cupola, air, or crucible furnace; 
also by charcoal blast furnace operators. Warm, hot, 
and superheated blasts are generally used for smelting 
ores to produce iron or other metals. Warm blast is 
air heated from 250 to 400 degrees F. Blast heated 
above 1,100 degrees F. is generally termed super¬ 
heated blast, and if the temperature ranges from 700 
to 1,100 degrees F. it is generally known as hot blast. 
There are two properties in the blast, the first being 
physical and the second chemical. With a temperature 
of 60 degrees F. and the barometer at 30 inches, air 
weighs about one-eight-hundred-fifteenth part as much 
as water.* The weight of blast passing through a 
furnace in smelting ore to produce iron is greater than 
the combined weight of the fuels, ore, and flux 
charged. Blast or air contains chiefly a mixture of 
two gases, nitrogen and oxygen, which is recorded 
by volume and weight in the following Table 14: 

♦Table 131, page 591, at the close of this work, gives the dif¬ 
ference in value of degrees between Fahrenheit and Centigrade 
methods. 



COLD AND HOT BLAST VS. COMBUSTION. 


71 


TABLE 14. 



Volume. 

Weight. 

Nitrogen. 

79.19 

20.81 

76.99 

23-01 

Oxyeren. 


100.00 

100.00 


As the blast is forced into a furnace or cupola, the 

oxygen combines with the carbon of the fuel and 
produces carbonic acid gas, which is two atoms of 
oxygen to one of carbon. This gas, in passing up¬ 
ward, takes up more carbon and is gradually converted 
into carbonic oxide, a gas which soon gains supremacy 
in lowering the high temperature necessary to liquid¬ 
ize ores or metals. By considering that a state of 
carbonic acid is necessary to liquidize, and that car¬ 
bon-oxide alone will not heat metals to a red hot color, 
we are in a position to fairly comprehend the differ¬ 
ence in degrees of temperature which ascending gases 
must have in reducing ores in a furnace or melting 
iron in a cupola. It is said that one unit of carbon 
passing to the state of carbonic oxide only yields 2400 
heat units centigrade, but when it becomes carbonic 
acid, 5,600 additional heat units are evolved, further 
illustrating the difference in temperature which the 
two states of carbon can create. 

The existence of carbonic oxide is essential in the 
blast furnace for the reduction of ores to produce iron, 
but not in remelting iron. In the cupola the less car¬ 
bonic oxide gas, the greater the economy, and, to 
decrease this gas, upper tuyeres are sometimes utilized. 
These supply additional oxygen to the escaping car¬ 
bon and convert it back more to carbonic acid gas and 















72 


METALLURGY OF CAST IRON. 


give greater heat in the cupola. This is so effective 
that where upper tuyeres are not used, the escape of 
carbonic oxide gas may often be so great that when it 
reaches the charging door and obtains oxygen from 
the air, it often creates such a combustion as to send a 
flame many feet above the top of the stack, causing 
much loss of heat. 

The following Tables 15, 16, and 17 show the amount 
of heat absorbed in smelting and that lost by radiation 
and in gases, according to Sir Lowthian Bell’s esti¬ 
mate, expressed in hundredth-weight heat units per 
ton of iron produced: 


TABLE 15.— HEAT PRODUCTION. 

Oxidation of carbon.. 

Contributed by blast 

- 93.455 


81,536 units 
11,919 “ 


TABLE l6.—HEAT ABSORPTION. 


Evaporation of water in coke. 

Reduction of iron. 

Carbon impregnation. 

Expulsion of CO 2 from limestone. 

Decomposition of CO 2.. 

Decomposition of water in blast. 

Phosphorus, silicon and sulphur reduced 

Fusion of pig iron. 

Fusion of slag. 


TABLE 17. —HEAT LOSS. 

Transmission through walls of furnace. 

Carried off in tuyere water. 

Carried off in gases. 

Expansion of blast, loss of hearth, etc. 


312 units 

33,108 “ 

1,440 “ 

5.054 “ 

5,248 “ 

2,720 “ 

4 ,U 4 “ 

6 ,6co “ 

16,720 “ 

- 75,376 


3,658 

1,818 

8,860 

3,743 


units 

(( 

<< 

H 


18,079 


93,455 

By increasing the height of furnaces from seventy 
to one hundred feet, as practiced at the present day, 
























COLD AND HOT BLAST VS. COMBUSTION. 


73 


much more heat is utilized than formerly when fur¬ 
naces were about forty to fifty feet high. This practice 
has greatly assisted furnaces in achieving their present 
large output and economy in making iron. This 
experience is one which the founder has also found 
advisable to follow in the construction of cupolas, as 
they are made to-day from four to twenty feet higher 
than they were fifteen years ago. The height now 
generally followed is about ten to sixteen feet from the 
bottom plate to the lower level of the charging door, 
whereas it used to be only from six to nine feet. The 
Carnegie Steel Co. has cupolas as high as thirty feet to 
the charging ring. 


CHAPTER X. 


EFFECTS OF BLAST TEMPERATURES IN 
DRIVING FURNACES. 

Hot blast is claimed to have been first introduced 

by Mr. James Beaumont in Scotland in 1825. Up to 
this time cold blast only had been used. The use of 
hot blast has increased in temperatures from 100 to 
1,500 degrees and higher. Every increase in tempera¬ 
ture in blast was found to effect more or less of a 
saving in fuel and improve the working of a furnace 
up to 1,700 degrees; over this it has not proved 
economical. When only 100 degrees was used it 
proved to be an advantage over the cold blast. Then 
200 degrees was used, showing better results than 100 
degrees, followed by 300 and 400 degrees, and upward 
until a temperature of 1,000 degrees was obtained, which 
was as high as iron stoves or pipes would stand the heat 
without being rapidly burned away. The knowledge 
that every increase in temperature had proved benefi¬ 
cial gave confidence that a higher temperature than 
1,000 degrees would prove still more economical, but 
in order to utilize a higher heat than 1,000 degrees, 
some other plan than ‘ ‘ iron stoves ’ ’ had to be devised. 
This improvement was not long in making its appear¬ 
ance. Different designs of stoves having all-brick flues 
which could not be damaged to any radical degree 
were introduced with great success, and the tempera- 


EFFECTS OF BLAST TEMPERATURES. 


75 


ture of the blast was soon raised by degrees until 
1,500 to 1,600 degrees were often utilized with benefit 
where a furnace had “ chilled ” or “ got off ”; but the 
general practice of high temperature of blast in the 
normal working of a furnace is not to exceed 1,300 
degrees, being kept at 1,100 to 1,200 degrees with 
brick stoves and 900 to 1,000 degrees with iron stoves. 
When a furnace is working well, any increase over 
1,200 degrees in the temperature of the blast is 
claimed by many to be more injurious in its results on 
the stock than beneficial in assisting a furnace to pro¬ 
duce a good yield of iron, or “drive well.” The 
reason that high degrees of heat in the blast will not 
cause the desirable and economical reduction of ore 
in the furnace, that high heat derived from the fuel 
will, is a phenomenon which all seem at a loss to 
understand. Experience has demonstrated that a 
temperature between 1,000 and 1,200 degrees is the 
most desirable to maintain. The temperature of the 
blast may be raised from 600 to 800 degrees with 
but little improvement, but let this 200 degrees in¬ 
crease be added to 1,000 degrees and the benefit 
derived is extraordinarily greater than any increase of 
200 degrees on a lower temperature. In the normal 
working of a furnace the best results are obtained 
with a temperature of blast ranging between 1,000 and 
1,200 degrees F. 

By reason of utilizing the waste gases of a furnace 
to heat cold blast, blast furnace practice excels all 
other industries in obtaining the greatest efficiency 
from fuel, as about 75 per cent of the heat generated 
from the solid fuel is utilized. This is attained where 
one ton of coke will produce one ton of iron; and vSir 


76 


METALLURGY OF CAST IRON. 


Lowthian Bell claims that where this is done all the 
economy is achieved that is practical to be expected in 
making iron, as long as the present fuel is used. To 
note the manner in which heat is produced, absorbed 
and lost, see Tables 15, 16 and 17, page 72. 

Pyrometers. Various methods are employed for 
measuring degrees of heat. Those of a crude nature 
consist, for example, in using dry sticks of wood, 
which when inserted in hot air take fire, indicating a 
temperature of about 650 degrees F. Again, sticks of 
zinc, if melted, indicate about 750 degrees. • To obtain 
a record of higher temperatures in a more accurate 
manner, many different kinds of instruments have 
been devised and in recent years have been largely 
adopted. A pyrometer recently designed and patented 
by Mr. E. A. Uehling, of Birmingham, Ala., in which 
the expansion and contraction of air between two 
small apertures is the principle used to denote tem¬ 
perature, is claimed to be giving excellent satisfaction. 
It is being largely adopted by blast furnacemen to 
record for them any variations in the temperatures of 
the hot blast or escaping gases, and enables them to 
regulate the workings of a furnace so as to give a 
greater output and produce a more uniform product 
than heretofore. 

The question of temperatures in driving a furnace fast 
or slow is one of interest. It will appear strange to 
the founder, as well as to others, that a furnace c^n be 
got so “ hot ” as to retard the speed of making iron, 
and also may result in “ scaffolding; ” nevertheless 
there is a limit to attaining temperatures best calcu¬ 
lated to drive a furnace to its utmost, which means ob¬ 
taining the largest tonnage possible in making iron. 


EFFECTS OF BLAST TEMPERATURES. 


77 


After this limit is reached, it would seem that too 
great a body of the ore was suddenly brought to such 
a swollen, gummy state, as to retard the proper ascent 
of the blast and gases. The first factor to give notice 
that a furnace is getting “ hot ” is an increase in the 
temperature of the gases and the refusal of the stock to 
descend as rapidly as - when the furnace is working in 
a normal condition. To retard the increase of heat or 
lower the temperatures to the best point, it has been 
found that increasing the blast pressure would often 
bring a “hot furnace” back to its normal working. 
By this method a greater volume of blast is admitted, 
which having a lower temperature than the incandes¬ 
cent stock in the furnace, naturally cools it down. 
Then, again, a plan is now largely adopted in having 
arrangements made so that cold blast can be turned on 
at a moment’s notice. This “brings a furnace ’round” 
more quickly and in a much better manner than by 
increasing the pressure of the regular blast which, it 
should be understood, will have its temperatures low¬ 
ered as much as is practical before being admitted. 

It is chiefly with brick hot-blast stoves that arrange¬ 
ments are provided for admitting cold blast to cool off 
a furnace, as these carry higher temperatures of blast 
than iron hot-blast stoves, as can be seen by referring 
to Chapter XI. The causes leading to “ hot fur¬ 
naces can be traced to excess of fuel, often brought 
about by using larger percentages than ordinary, which 
may be called for by reason of having to use small, or 
what is thought to be inferior coke or fuel, and again 
in burdening a furnace with fuel in order to laise the 
silicon in the iron or guard against “ scaffolding” or 
“slips” from the use of fine ores, etc. It may also be 


78 


METALLURGY OF CAST IRON. 


caused by a furnace perfecting combustion of its own 
accord to such a point as to overreach the best temper¬ 
ature for driving well. It may be said that brick 
stoves have many advantages over iron stoves in per¬ 
mitting a furnaceman to regulate the temperature of 
his furnace so as to drive it well and increase or di¬ 
minish the silicon or sulphur in the iron, and that a radi¬ 
cal change is generally noticed in this direction when 
cooling down a “ hot furnace,” as by such procedure 
the silicon is often materially decreased and sulphur 
increased. 

Humidity of blast. It is generally conceded by ex¬ 
perienced furnacemen that a furnace will work better 
and produce more iron in cold than in hot weather. 
It is said that in June, July, and August a furnace 
never produces tonnage to equal other months in the 
year. The air is generally dryer in cool than in warm 
weather, and it is now an accepted fact that the extra 
humidity in the summer air over that in cold weather is 
the cause of the less tonnage in the summer months. 
Some will think the heat imparted to the blast would 
drive out all the moisture, but this is claimed to be 
simply transformed into a vapor which passes into the 
furnace as steam. It has been estimated that twenty 
tons of water are often transferred, by the blast, to 
the interior of a furnace per day by reason of the high 
humidity of air in summer months. Further com¬ 
ments on this subject can be found in Chapters IX. 
and XXXIX. 


CHAPTER XI. 


PLANS AND METHODS OF WORKING 
BRICK AND IRON STOVES IN THE 
CREATION OF HOT BLAST. 

A knowledge of methods used in creating hot blast 
at the blast furnace is valuable to the founder and 
moulder, as it presents good ideas for the benefit of 
those desiring to design appliances for the purpose of 
creating warm or hot blast for any purposes. 

The terms “iron stoves” and “brick stoves” are un¬ 
derstood to mean, in the case of the former, that the 
cold air passes through iron pipes, while with the lat¬ 
ter, in being heated to make hot blast, it passes through 
flues or checkered work composed wholly of fire brick. 

The iron stove is fast disappearing and being re¬ 
placed by the brick stove, owing to the ability of the 
latter to create the highest temperatures in blast, 
which allows iron to be made more cheaply than where 
a temperature no higher than 1,100 degrees F. can be 
created, as with iron stoves. A further reason for this 
displacement is that the brick stove is less expensive, 
in matters pertaining to repairs and “shut-downs,” to 
keep a furnace running steadily, also in giving more 
gas for use under boilers, etc. than iron stoves. 

The operations of brick and iron stoves differ in 
their methods of being “in blast.” The brick stoves 
generally go out of blast every hour, whereas the iron 


8o 


METALLURGY OF CAST IRON 


stoves generally run steadily -is Feet 

for six weeks at a stretch, 
and have been known to 
run without interruption for 
several months. 

This difference in 
their operation is 
due to this principle. 

Brick stoves now 
in use require the 
cold air to abstract 
heat from the bricks 
comprising the flues 
in the ovens, after 
the combustible or 
heating gases have 
all been shut off, 
and in the “ iron 
stoves ’ ’ by reason 
of the iron pipes 
or flues through 
which the cold 
air passes, be¬ 
ing separated 
from union 
with the gas¬ 
es; hence the 
iron stove can 
run steadily, 
whereas the 
brick stove 
runs only at 
intervals. 



FIG. 


14.—MASSICK & CROOKE PATENT BRICK 
BLAST STOVE. 



























































































































METHODS FOR WORKING HOT BLAST STOVES. 8l 

The short duration of the brick stove being “in 
blast ’’ is due to the rapidity with which the introduc¬ 
tion of cold air abstracts heat from the brick work. 
The temperature of a brick stove decreases from ioo 
to 300 degrees F. in one hour’s time. With the plan 



of stove shown at Fig. 14 four stoves are required 
to keep a furnace steadily in blast. Of the four stoves, 
only one is generally in blast, although two may run 
together for the whole of one turn of the stoves. The 
plan generally followed is to “put on’’ the stove going 





















































































































































































































82 


METALLURGY OF CAST IRON. 


in blast a few minutes before the one going out of 
blast is shut off. 

The sectional views of iron and brick hot blast stoves 
shown in Figs. 14 and 15? respectively, aie of stoves in 
use within a “stone’s throw’’ of the author’s foundry. 
The brick stoves shown are of the most modern type, 
recently built, and are said to be giving excellent satis¬ 
faction. Before these stoves were built, iron ones 
were used by the same furnace. The four stoves are 
said to have cost $40,000, and by their adoption the 
owners were enabled to produce pig iron 30 cents per 
ton cheaper than when the iron stoves were used, 
owing to the brick stoves causing the furnace to use 
less fuel and give a larger yield of iron, also cheaper 
cost of repairs than those required in iron stoves. It 
may seem a small saving for the investment of $40,000. 
When pig iron was selling for from $30 to $50 per ton 
and the furnaceman had a margin of profit of from 
$15 to $30, no one thought of investing $40,000 just 
to save 30 cents per ton on iron made. When $10 to 
$14 per ton is about all a furnaceman can get for his 
iron, as is now often the case, a saving of 30 cents per 
ton is quite an item, especially so if it will permit one 
furnaceman underselling another and leave a few cents 
profit on his sales. 

There are several different types of brick hot blast 
stoves now in use, and it now seems as if it will be but 
a few years before iron stoves will be almost wholly 
abandoned, mainly because the brick stove can make 
iron more cheaply than the iron stove. A large num¬ 
ber of furnaces are still using iron stoves, but as soon 
as they are worn out, or competition gets too keen, they 
will no doubt be largely replaced by the brick stoves. 


Methods for working hot blast stoves. 


However, a description of some of the main features 
and principles involved in “ iron stoves ” cannot but 
be of value to many. 

The plans and workings of an iron stove should first 


-T 




EE 





- 38 -— 



I 


FIG. l6. 


be considered. There are several different methods 
used in piping an iron stove. Those commonly em¬ 
ployed have the inverted U and straight pipes, as 
shown in Figs. 16 and 17. The inverted U pipe in 
Fig. 16 is the same as those used in the iron stove 
illustrated in Fig. 15. This oven contains forty-four 
of such pipes, there being eleven in a row and four 
rows in the length of the oven. The length and height 
of the oven are shown. The width is twelve feet. As 
the pipes stand up in the oven there is about three 

inches space between them. The 
knobs seen at T, Fig. 16, form 
the space of division between them. 
The section seen in Fig. 17, page 
84, is what is called “ straight 
pipe.” The division bar X answers the same purpose 
as making the pipes of a U form, owing to the rib X 
running up within about six inches of the top end of 
the pipe, when erected in the oven. A similar parti¬ 
tion as at X is also in the bed pipe; this causes the 
blast to pass up one side and come down the other, 
thus serving the same purpose as the pipe at Fig. 16. 

The straight pipes have the advantage of being more 
easily handled in taking them out of an oven when 
they burn out or crack, as they often do. The top of 
the oven is so constructed that the plate can be re¬ 
moved to permit bad pipes being hoisted out by means 
of an erected pole on the outside of the oven. It is 
far from being an easy or pleasant job to replace burnt 







8 4 


METALLURGY OF CAST IRON. 

or worn-out pipes. For this reason much care is ex¬ 
ercised to prevent the temperature rising above 1,100 
degrees in the oven. 

There is a plan used in iron stoves of suspending the 
iron pipes from the top of the oven instead of letting 
them rest with their weight on the “bed pipe,” as 
shown in Fig. 15. This plan prevents the iron pipes 
from “buckling” or bending from their own weight 
when they get red hot. 

The usual plan adopted for heating cold air to 
make “ hot blast ” in the iron stove will be readily un¬ 
derstood by a study of the design illustrated in Fig. 
15. The arrow seen at A, Fig. 15, is the point at 
which the cold air enters the iron pipes in the hot blast 
oven. As soon as the cold air enters the 
first “bed pipe” E, it takes the direction 
shown by the arrow in the pipe B; passing 
from this to the “bed pipe” F, then travel¬ 
ing up the pipe D and down into the bed 
pipe H, continuing such a line of travel through four to 
six more pipes, according to the length of an oven, un¬ 
til the blast reaches the outlet at K on the right, from 
which it then enters the blast furnace as “ hot blast.” 

The action of gases is next to be considered. A point 
to be understood is that of the means employed for 
heating the oven or iron pipes to create “ hot blast.” 
This is accomplished through the use of waste gases, 
which escape at the top of a furnace, and are passed 
down through the “down-comer,” seen on the 
right, to a flue N N, and then rising into the ovens 
through the openings M and P, until they reach the 
combustion chamber R, where they ignite as soon as 
they reach the point S, by reason of the gas being met 







METHODS FOR WORKING HOT BLAST STOVES. 


by a fresh supply of oxygen or air ancl the heat of the 
oven The chimney seen on top of the ovens at W 
creates a draft and permits the smoke or dead gas to 
escape. All the space about the pipes B and D is 
called the “ combustion chamber,” and when the gas 
is burning in the oven this space area is filled with a 
flaming gas fire. 

v Should the furnace go out of blast for any reason to 
exceed two hours, the oven will generally cool down to 
such a degree as to be very liable to cause an explo¬ 
sion when the gas begins to enter. Again, the oven 
being cold, could not heat the blast at the start to any 
effective degree, and hence less iron would be pro¬ 
duced, with a chance of also promoting “ chilling ” in 
the furnace. To prevent or guard against such ill re¬ 
sults, a wood or coal fire is generally built in flues P 
by opening the doors V. By such a plan the heat of 
the oven can be maintained to 700 to 800 degrees. It 
is not infrequent that items are noticed in the trade 
and daily papers speaking of some furnace having had 
a gas explosion. A cold oven is often the cause, and 
furnacemen watch this point very closely. Not only 
is it necessary that the ovens be hot when the gas from 
the ovens first enters them, but it is also desirable that 
a flame be burning in the oven to insure the gas ignit¬ 
ing. Some furnacemen will take no chances in this re¬ 
spect. If they shut down but for half an hour they will 
either have some dry wood or a few lumps of soft coal 
placed in the oven so as to insure a flame therein when 
the furnace begins to send its gas down the “ down¬ 
comer.” A gas explosion can cause great damage, 
and the wise take no chances or risk with it. 

The color of the gases escaping from the chimney 


86 


METALLURGY OF CAST IRON. 


W, and also of the flame in the ovens, affords an experi¬ 
enced furnaceman much knowledge of the condition 
of a furnace or what results may be expected in its 
workings. In this respect, also in regard to explo¬ 
sions, the same is to be said of a brick stove as of the 
iron one, and a close watch is generally kept of the color 
and action of the gases. The gas, as it escapes from 
the top of a furnace in its passage downward to the 
iron or brick oven, is chiefly in the form of carbonic 
oxide and may often not have a temperature of 300 de¬ 
grees of heat, although it generally ranges from 400 
to 500 degrees as it passes through the “down-com¬ 
er” to the ovens. This form of gas is an explosive, 
requiring air to make it combustible. This element it 
receives after it has entered the ovens, the air being 
drawn from outer channels or flues in the brick work 
of the iron stoves, as at H and F in the brick stove; 
this action creates the flame in the ovens just cited, 
which then raises the temperature to the degrees above 
noted. If the gas were allowed to pass into the oven 
in the state in which it comes from the top of a furnace 
through the “down-comer” without receiving a suffi¬ 
cient siipply of air, the gas would be of little value in 
raising the temperature of the blast confined in the 
pipes on its passage to the furnace. 

The plans and working of a brick stove are as fol¬ 
lows: The line of the arrows seen in Fig. 14 displays 
the various channels through which the cold blast 
travels after entering the brick stove at E, seen at the 
end of the cold blast inlet pipe. The direction of the 
cold blast in being heated is directly opposite to that 
taken by the gas coming from the furnace to heat up 
the walls and various channels and checkered brick 


METHODS FOR WORKING HOT BLAST STOVES. 


work in the stove. This is the plan followed in all 
modern brick stoves. The gas in leaving the “ down¬ 
comer ’ ’ is carried through gas mains to V, where it 
passes the gas valve at X and enters the furnace at 
H. Before the gas is turned on, the cap K, which 
closes the gas inlet while the blast is passing through 
the stove to be heated, is removed and the gas valve 
slid up so that the end of the pipe at X is about even 
with the face of the gas inlet. The pipe X, being 
smaller in diameter than the hole of the gas inlet at 
H, permits air to unite with the gas as it enters the 
stove, thereby causing combustion or ignition of the 
gas at the entrance before it passes to the combustion 
chamber, where it receives more air by means of the 
air inlet T, which is opened when the gas is turned on. 
At T, W and D are seen points at which valves are ar¬ 
ranged for opening or closing the passage of air or 
gas, as the case may be. When the gas is being turned 
on, the valve D is opened. As now shown, it is closed 
so as to prevent any gas escaping up the chimney P. 
Before the gas is turned on, the valve D is opened so 
as to create draft and permit the dead gas and flames 
to escape through the chimney. The valves T and W 
are closed when the gas is on, as will be evident to 
any making a study of the plans shown. In a general 
way the blast is on a stove for one hour and the gas 
for three. Three stoves are generally on gas while 
one is in blast, unless one is being cleaned of the caked 
flue dust which rapidly gathers on the combustion 
chambers for a distance of about twenty feet in height, 
and on the bottom of the stoves, which have openings 
as at K and S for getting at or cleaning out the stove, 
or, if shut off, for repairs. 


88 


METALLURGY OF CAST IRON. 


The valve at T is arranged with piping, through 
which water runs in order to protect the exposed parts 
of the valve from burning out. The valves W and D 
do not require the presence of water, for the reason 
that when the gas is on, the brick work of the stove 
absorbs the greatest heat at its bottom, which pre¬ 
vents the highest temperature being confined to the 
upper part of the stove. One stove, when a furnace 
is working well, is all that is generally “ in blast; ” ■ 
but if there should be a “ slip ” to chill a furnace or 
make it work cold, two or three stoves are often put on 
at one time for a short duration to assist in raising the 
temperature in the furnace so as to restore it to its 
normal condition, after which the additional stoves are 
taken off and the work continued with but one, as in 
ordinary practice. 

The four stoves are placed together as closely as is 
convenient to leave room for working around them. 
They cover an area of ground about 40x50 feet. The 
four stoves are connected by band pipes and separate 
valves, so that the cold blast coming from the “blow¬ 
ing tubes ” and the hot blast leading to the four stoves 
come from and lead into one main pipe. The pipes 
which convey the hot blast to the furnace are either 
coated with an asbestos covering or have their interior 
lined with fire brick, the same as is done with the 
“ down-comer” which carries the dead gas from the 
top of the furnace down to the combustion chamber 
of the hot blast stoves to protect them and prevent 
loss of heat. 


CHAPTER XII. 


TAPPING-OUT AND STOPPING-UP FUR¬ 
NACES AND CUPOLAS. 

It has taken much time, study, and experience to at¬ 
tain the present perfection in controlling the output of 
a modern furnace. The history of blast furnaces 
shows many disasters in “breakouts,” “boils,” and 
explosions. When all is working well about a furnace 
everything seems very simple and as if taking care of 
itself, but it is when all does not go well that one is 
impressed with the fact that furnacing is often more 
like hades let loose than a paradise of comfort, ease, 
and pleasure. An observing founder standing at a 
distance watching a furnace being tapped might often 
be at a loss to understand why a cupola cannot have 
its ‘ ‘ breast ’ ’ stopped the same as the ‘ ‘ notch ” of a fur¬ 
nace. The founder often has trouble with cupola tap- 
holes, which when once started to work badly will 
often continue to do so throughout the balance of the 
heat. The secret of the furnaceman being able to stop 
a notch by hand in the way it is generally done, is 
that the metal, when all is working well, is left lower 
than the notch-hole, about as illustrated at the level O, 
Fig. 18, page 90. How the metal goes down to such a 
low level as shown is a puzzle to the founder who has 


9° 


METALLURGY OF CAST IRON. 


never seen a furnace. 
The tapping-hole K 
is generally made at 
an angle somewhat 
as shown. After the 
metal has run out all 
it will by force of 
gravity, the blast 
pressure is increased 
above the ordinary to 
drive or siphon it out, 
as called by some, to 
about the level shown 
at the dotted line O. 
With the weight of stock bearing down on the molten 
mass in a crucible and blast pressure of io pounds or 
more to the square inch, it seems reasonable to expect 



FIG. 1 8 . 


the results described. We know the weight of stock and 
pressure of blast exerts such a driving-out influence, 
from the fact that when about two-thirds of the pig beds 
are poured, the metal will often almost stop running, at 
which point the blast pressure being increased a fourth 
more metal will often be forced out, and the more 
acute the angle of the notch, so as to carry its opening 
lower into the crucible, the more metal to a depth of 
about 15 inches below the level of the bottom of the 
iron trough can be siphoned out in tapping a furnace. 
A question which suggests itself here is the reason 
for having such a body of metal below the level of a 
notch-hole. The great depth sometimes attained is 
not really desired, but is caused by the liquid mass 
burning out the bottom brick-\york. 

When “blowing=in” a new furnace, the bottom bed of 





























































































TAPPING-OUT AND STOPPING-UP FURNACES, ETC. 91 

the hearth or crucible is not much over four inches below 
the level of the notch, but continual running and “ fast 
driving of a furnace soon cut out the bottom lining, 
so that it is no uncommon result for metal to burn the 
bottom down two to three feet below the level of a 
notch, as indicated by the dotted line S in Fig. 18. 
Furnacemen claim it is not until a bottom is cut down 
for a foot or two that the best output and quality 
of product can be obtained, and also that a deep bed 
is very desirable to help maintain a uniform product. 
Often has a furnace cut the bottom out to such a depth 
as to force an opening for metal to pass downward 
through the ground or outward through the sides, 
about as is indicated by the lines N, M, and H, Fig. 18. 
The havoc such an escaping body of metal can make, 
if bursting out, as it often does, into a reservoir of 
water, which is always more or less deep around the 
hearth of a furnace at N, can be but partly conceived. 

The mass of liquid metal in the bed of a furnace 
often weighs 50 to 100 tons. This often solidifies- 
and lies in a furnace until it is torn down, or the 
hearth portion removed to permit its being broken by 
dynamite. It has happened that, through a furnace 
“ getting off ” or working badly, the bed of metal has 
solidified above the level of the notch, so that to tap 
the metal out of the furnace it would have to be 
drawn off at the flushing or slag-hole at A, Fig. 18. 
Some furnaces have run for a week or two in this 
manner before they, were able to get the _ solidified 
mass melted down, so as to again draw metal from the 
notch-hole. A furnace in this condition must be 
tapped much oftener than when it can be tapped at 
the regular notch. It is often surprising how rapidly, 


9 2 


METALLURGY OF CAST IRON. 


through a furnace getting cold, the bed of metal in the 
hearth will solidify, and then again how, when a 
furnace is working hot, it will often cut out such a 
solid mass of iron; but generally, like all workings of 
mechanical affairs, the evil is prolonged more than 
the good is hastened, when trouble once begins. 

Fig. 19 shows the effect of a chill in a furnace caus¬ 
ing metal to solidify around and above the notch. This 
is one form, and another form, instead of having a 
chill all around the sides with liquid metal in the 
middle, may have one side solidified while its opposite 
is in a fluid state. Solidification of such masses 
generally occurs by reason of scaffolding, cooling off 
the furnace, and then letting a mass of chilled stock 
slip down to the tuyeres or lower into the hearth. 
There are two forms of such evils resulting from a 
slip, the first being the solidification of metal as above 
described, and the other what is called a “ lime-set,” 
which is generally caused by reason of a furnace 
carrying a heavy burden of limestone, and the furnace, 
becoming cold from “scaffolding” or any other bad 
working, chills the lime so that it becomes too thick 
to flush out, and “ sets ” in a solid state in the crucible 
or at the tuyeres. 

Furnacemen generally fear a “ lime set ” more than 
that of molten metal solidifying, for the latter can be 
melted away much more readily than the former. Lime- 
sets have been so serious that furnaces have had to 
“blow-out” to remove them. A method sometimes 
employed to gain access through solidified iron, which 
had closed up tuyeres, or a “ notch,” so as to prevent 
its being tapped, is that illustrated by the hydrogen 
blow-pipe at A, Fig. 19, page 93. As used in this case, 


TAPPING-OUT AND STOPPING-UP FURNACES, ETC. 



FIG. 19. 


it is simply a 2-inch 
gas pipe leading 
C] from the hot blast 
pipe (cold blast can 
hl> also be used), into 
which a % -inch pipe 
D carries a stream 
of coal oil. This is 
contained in a can 
sufficiently high to 
force the oil out and 
overcome the blast 
pressure at the outlet; there it ignites by combination 
of the air and oil. Sufficient heat is thus generated to 
melt the iron or enable it to be knocked away. Space 
is made, in this manner, which admits the blast and 
metal blowing out to further cut away the solid iron to 
a point warranting the replacing of the notch for regular 
working. In some cases a coke or coal fire may be en¬ 
cased in front of the blow pipe, and the stock is to 
be cut away as illustrated by the small lumps of fuel 
seen at E, Fig. 19. The principle involved in this 
process is one which may often be practically applied 
by the founder in preparing a casting to be burned, by 
bringing the point ot fracture to almost a molten state, 
thereby saving labor of melting and handling a large 
quantity of molten metal. It may at times also be 
found of value in assisting to cut away heavy bodies of 
iron that may be found almost impossible to be other¬ 
wise manipulated. In using this device to cut out a 
notch of a furnace, great care is exercised, as it may 
cut through the chilled material and, without warning, 
the molten contents may burst out with such force as 
























































































94 


METALLURGY OF CAST IRON. 



FIG. 20. 


6V 


to empty the furnace in a few minutes. Men have been 
struck by such outbursts and almost buried alive in a 
pool of metal before assistance could be rendered. 

The process for hand=tapping, when all is working 
well with a notch of a furnace, is first to take an iron 
bar and prick into the stopping clay, starting a hole as 
seen at the entrance K, Fig. 18, the “keeper” being 
careful to give it the shape and angle desired. As the 
clay is loosened, a ^4-inch rod, having a flat lifter about 
1^2 inches square on its end, as seen in Fig. 21, be¬ 
low, is used to pull the loose clay up out of the hole, 

which is generally 
made about 4 inches 
in diameter at the 
top, tapering down 
to 2*4 inches at the 
bottom. Picking by 
hand bars and lifting 
out the loosened clay 
is continued until the 
solid clay shows by 
its red heat that its 
thickness preventing the metal bursting out is not 
over 3 inches; then a steel bar of about 1 inches 
diameter having a sharp point is placed as shown in Fig. 
18, the upper end resting on a piece of pig metal 
thrown across the top of the iron trough, as seen at T. 
A sledge is now used at the end F, the bar in the 
meantime having its point guided by hand so as to cut 
around the edge of the hole. This is continued until 
metal commences to ooze out slightly, when the bar is 
driven through the started body of the clay into the 
metal seeking to force itself out. The bar is then 


‘iST 


U—12- 


■0 


FIG. 21. 



140 




FIG. 22. 













TAPPING-OUT AND STOPPING-UP FURNACES, ETC. 95 

pulled out, ill which movement, should any difficulty be 
experienced, a device as seen at P, Fig. 18, is used, which 
by sledging on the end of the wedge shown, backs the 
bar out of the notch. Sometimes, instead of the device 
shown, a stout ring will be used, and by inserting the 
wedge as shown a similar result is insured. This 
device is a simple affair, and should suggest to many 
founders a remedy for difficulty often experienced in 
pulling back bars driven into the breast, tuyeres or 
slag-holes of a cupola. 

After a bar has been removed from the notch, the 
metal generally flows out with a fair speed, but should 
lumps of dross or fuel impede its passage, a smaller 
bar than the one used to tap it is generally inserted in 
the notch-hole, and by working it up and down the 
passage is eventually cleared so as to permit the flow 
desired. It is not infrequent that the metal rushes 
out with too great speed, often coming with an unex¬ 
pected burst, so as to strike the “ keeper ” with a 
spreading sheet of rushing metal if he is not continually 
on his guard. After a furnace has been tapped and 
the iron commences to flow well, a cover composed of 
fire brick held in an arch shape by a cast iron bracket 
casting is .swung by means of an iron arm close up to 
the furnace front at the cooler V, Fig. 18, and let 
rest on the edge of the trough shown. Any space 
between this cover and the furnace shell is closed by 
means of sand beipg thrown around this section. This 
cover prevents the metal and slag from blowing up 
against the shell of the furnace and burning it out. 

An arrangement which is generally used at every 
hand-tap to assist in lessening the force of the stream 
is a stopper, as seen in Fig. 22. The end W, being 


9 6 


METALLURGY OF CAST IRON. 


held at the month of the notch, can, if there is not too 
great a force, often almost stop the escape of metal. 
This stopper is made by rolling a i^-inch rod in a 
stream of slag as the furnace is being flushed out. 
Should the metal force itself out too fast at any time 
during a tap, the blast is slackened or stopped, until 
the metal has flowed off all it will of its own gravity, 
when the blast is again put on, and the increased 
pressure then drives out the metal and slag as above 
described. This end achieved, the blast is then com¬ 
pletely shut off and the notch stopped. 

The process of stopping the notch by hand is pro¬ 
ceeded with as rapidly as possible, in order to prevent 
loss of time in making iron. The first thing done is 
to throw a. sheet-iron plate across the top of the iron 
trough; which, covered over with sand, protects the 
men from the heat of the trough, and permits them to 
come directly over their work. The notch at this 
stage greatly resembles a crater that has died down 
after vomiting its lava. Lumps of dross and fuel will 
be found sticking to its sides, which have been great¬ 
ly increased in area from the effects of the “ blow.” 
A bar is used to loosen this debris , and then an iron 
scoop pulls it out of the notch-hole. After this debris 
has been removed as well as the inflowing slag will 
permit, the bar is again used to push down into the 
crucible any lumps which may be sticking to the 
sides of the notch, and a bar of the same shape as Fig. 
21, only made of round iron, is now used to press down 
into the crucible the dross and slag which endeavor to 
rise to fill the notch-hole. This done, the bar is hasti¬ 
ly removed, and men standing with two shovelfuls of 
clay toss it into the notch-hole, the clay is then quickly 


TAPPING-OUT AND STOPPING-UP FURNACES, ETC. 


rammed down as far as it is possible with the rammer 
rod just described. After as much clay is pressed 
downward with these rammers as is found possible, 
then a round stick about 3 inches in diameter at the 
small end and 3 ^ inches at the top, having a ring to 
prevent the sledging splitting the timber as seen at 
Fig. 20, is inserted into the notch and driven with two 
sledges down to the bottom, thus driving the dross 
and clay back into the crucible, as far as possible, to 
make a solid filling of clay in the notch at its bot¬ 
tom. This method of packing having been performed 
half way up the notch, the packing stick is removed, 
the blast started, and the balance of the notch is then 
filled with clay packed with hand rammers. A stream 
of hot blast is now turned on the top of the notch and 
the clay grouting used to coat the iron trough, so that 
at the next tap there will be no dampness to start a 
“boil.” 

The above description is one plan of hand-stopping a 
furnace, but lately a machine has been designed to be 
worked, by steam forcing out a stopper,* by which a 
furnace can be stopped at any part of a tap without 
shutting off the blast. 

Many furnaces are now using stopping machines. 

They prove valuable in many ways, especially in per¬ 
mitting a more steady blast, and which gives a greater 
output and more uniform grade of metal and greatly 
lessens the chances for scaffolding due to a more steady 
heat being maintained in the furnace. It is said that 
all users of these stopping machines praise them very 
highly, and it now looks as if it would not be long 
before all furnaces would adopt them in their practice, 


* Patented by S. W. Vaughn, Johnstown, Pa. 



g8 


METALLURGY OF CAST IRON. 


especially those using fine grades of ores, as any stop¬ 
page of blast is apt to cause a temporary chill and to 
retard good working of the furnace. 

Not all grades or kinds of clay are .suitable for stop¬ 
ping notches. It must be of a quality to withstand 
fire to the best possible degree. Some use a good 
grade of fire clay and others grind up old crucibles tOi 
mix with the fire clay in an effort to improve its heat- 
resisting qualities. The clay is mixed to a consistency 
about like that found good for cupola stopping clay, 
and in some places is prepared in pans crushed by 
heavy rollers. 

The success of stopping a notch by hand being due 
to the fact of having the metal lower than the level of 

the notch, affords the furnace an 
advantage not permitted to the 
cupola. Conditions in the latter 
calling for a “ bottom ' drop, ” 
every heat makes it most desir¬ 
able that no metal should remain 
in the bottom of a cupola when a 
heat is finished. For this reason 
the bed of a cupola as seen at Y, Fig. 23, is generally 
made on a slant, and the tap-hole placed at its lowest 
level, as seen at R. With such an arrangement, when 
difficulty in tapping and stopping once commences, it 
often causes the cupola tender much harassing labor, 
and the founder loss in casting. Any one desiring 
further information on tapping out and stopping up 
cupolas is referred to “ American Foundry Practice,” 
page 331. 


































CHAPTER. XIII. 


MOULDING SAND, CASTING SAND, SAND- 
'LESS PIG IRON AND “ OPEN 
SAND ” WORK. 

The many devices which are employed by furnace- 
men in controlling the distribution of 20 to 100 tons 
of molten metal, when tapped, display experience and 
knowledge which the foundry manager and moulder 
can often well utilize in founding. Every branch of 
handling molten metal has its own little “ tricks ” in 
practice, which have often taken years to perfect, and 
I propose now to illustrate some of those involved in 
controlling metal and making “ open sand” moulds 
and casts at a blast furnace, as the information and 
ideas such study imparts, even though furnaces should 
abandon casting pigs in sand beds, as referred to on 
pages 113 to 116, will prove of value in many ways to 
general founding. 

A moulder, however well experienced, who has 
never seen a blast furnace, would be very liable to 
make bad work of things at the start, should he at¬ 
tempt, without any instruction, to direct the making 
and casting off of a floor of pigs. In preparing a 
moulding bed for making pigs, the floor is dug out 

Lore. 


100 


METALLURGY OF CAST IRON. 


from 2 to 3 feet deep, and then filled up with a medi¬ 
um grade of bank sand, of a very open, sandy nature. 
The reasons for going down to such a depth to simply 
mold pigs that are not more than four inches deep, 
also for using such a coarse grade of sand having 
very little binding qualities about it, are found in the 
desirability of having conditions as favorable as pos¬ 
sible for permitting the escape of steam from any ex¬ 
cess of moisture or water, which the sand may contain, 
or for draining downward, and hence lessening the 
chances of a “boil.” The moulder must bear in mind 
that when once a stream of iron is started, the furnace- 
man cannot plug up a “run-out” or dampen the 
ardor of a little ‘ ‘ kick, ’ ’ the same as when pouring a 
mould, and hence the precaution of not being depen¬ 
dent upon one’s judgment to get sand just the right 
11 temper, ’ ’ etc. Where sand is as open as is generally 
used for pig beds, and as deep in the floor as above 
described, water, after having been absorbed to a cer¬ 
tain point, will, to a large degree, filter through coarse 
sand towards the bottom of its depth, so that should an 
,excess of water have been used, the chances are it will 
not cause the “ boil ” it would certainly do if the sand 
was of such a character as that generally used for green 
sand molding in a foundry. Another point which 
makes it desirable to use such open-grained sand is 
that of saving labor in mixing sands. About all the 
mixing that furnace sand generally gets is what the 
force of water from a two-inch nozzle gives it. I have 
seen such a stream play steadily on one spot for two 
or three minutes and no attention paid to it. If 
moulding sand in a foundry received such abuse, the 
iron would mostly go to the roof the moment it struck 


MOULDING AND CASTING PIG IRON, ETC. 101 



the sand. But like all else in mechanics, there is a 
limit to abuse, and too much carelessness in wetting 
down the floor of a casting house can result in disas¬ 
trous “boils.” 

rioulding pig beds is generally done by three men, 
who will mould up 
fifteen to twenty 

beds in about one_ jp _ ,s _ jo 

hour. The main I"*™"* —7 

runner leading to ' fes 
the pigs Nos. i, 2, 

3 , 4, 5 . 6 and 7 , FIG ’ 25 ' 

Fig. 29, page 103, 


^ „ _ V. ’ -l ' v/.'-vIv T _r..., 

is called the ‘ ‘ sow ^ 
runner.” There 
are generally from 
24 to 28 pigs to a 
sow. Each sow is 
leveled, likewise 
the pigs connect¬ 
ed to it, but each 
bed is, in com- 



F.«rrw^rq 

•vS'-V-v 
. v* •« »; 

i,V *,• •.*%' 


mencing from the 
lower end, made 


r •'.**.* 


£v-\ : 



c-.v.’.-.i luiyiVi* 



FIG. 27. 




































































102 


METALLURGY OF CAST IRON. 


one or two inches higher as they approach the last 
bed, so as to conform closely to the incline of the 
main or “iron runner,’’ as it is generally called, which 
has a fall of about eighteen inches in one hundred 
feet. A greater fall than tills would generally cause 
the iron to flow with too great a rush, and should it 
get away from the furnace any faster than usual, the 
chances are it could not be controlled, and instead of 
its being distributed as desired throughout all the pig 
beds, the lower two or three beds would be overflowed, 
and a “ boil ’’ easily started by reason of a large area 
of floor space being all covered with a plate of fluid 
metal, permitting no escape of gas and steam from 
the sand cores between the pigs. The founder often 
receives pigs united together, and often much thicker 
in depth than usual. , These are called “ jump cores,” 
and are formed by reason of the body of sand in 
the mold separating the pigs, being raised or pressed 
to one side by the action of too quick a flow, poor 
sand, or a little “boil.” It has been no uncommon 
occurrence for metal to come so fast down the iron 
runner that it could not be controlled, and by reason 
of covering over a large area, cause a whole tap to go 
under the drop, or, worse still, require dynamite to 
break it up sufficiently small to be charged into the 
furnace, along with the ore, or sold for scrap metal to 
be re-melted in air furnaces or big cupolas. 

.The making of the iron runner is generally the work 
of the “ keeper.” Figs. 24, 25, 26 and 27 show differ¬ 
ent views of such runners, and Fig. 34, page 104, a 
perspective view of the whole. 

After a furnace has been tapped, the metal often 
comes slowly, to prevent it from chilling until its 






moulding and casting pig iron, etc. 


io 3 

































































































104 METALLURGY OF CAST IRON. 

speed is sufficient to fill the runner as desirable, a little 
knoll, as at A, Fig. 24, is generally formed in the 
‘ ‘ iron runner, ’ ’ as shown. This causes a sufficient body 
of metal to collect and keep itself fluid until the 
flow is increased enough to overflow the knoll, by 
which time the chances are the flow will have in¬ 
creased to such a degree as to send a fair stream 



FIG. 34.—PERSPECTIVE VIEW OF A CASTING HOUSE. 


down the iron runner. The iron in first flowing down 
the runner carries more or less slush of iron and dirt 
in the front of its stream. This will often pile up so 
as to require to be broken by means of a wooden pole 
in the hands of a man, as seen in Fig. 34. As soon as 
the metal has reached and filled the lower bed, a “ cut- 













MOULDING AND CASTING PIG IRON, ETC. 105 

ter,” as shown at Fig. 30, and in the hands of the 
man at the left in Fig. 34, is then quickly placed 
with pressure so as to be bedded into the main run¬ 
ner, as seen at B, Fig. 24. A few moments before this 
is done a man with a ravel, as seen at Fig. 34, pulls 
away the mound of sand, closing the connection from 
the “ iron runner ” to the “ sow,” as seen at C and D, 
Fig. 24, also at E, Fig. 29, to make an opening, as 
seen at F, Fig. 24. The top level of the pig beds 
should be below the level of the bottom of the main 
runner in order that all the metal may be drained from 
the main runner; and, again, the pig beds should 
not be too far below the level of the bottom of the 
main runner, as this would cause the metal to rush 
from the main runner to the sow with a force very 
liable to cut up the sand where the metal would strike 
the bottom level, or wash away the cores between the 
pigs. The distance sought for is about that shown in 
the cuts, Figs. 28 and 29. If the moulder would con¬ 
sider trying to make a mould with what is generally 
termed a medium grade of bank sand, having the life 
pretty well burned out of it, he would then be in a posi¬ 
tion to understand how easily a rush of metal could cut 
up a pig bed of moulds, and the necessity for having 
certain conditions prevail, even if it is only “ pigs ” 
that are being moulded and cast. As the metal 
flows down the runner, much of the sand floats with 
the iron; but as pigs are not finished, or condemned, if 
they are a little rough on their surface from dross 
or sand, there are no serious objections as long as 
it is not sufficient to impede its passage to the pigs. 
At H, Fig. 29, is seen the “ ravel ” as it is placed 
in the sand ready to make an opening to admit 


io6 


METALLURGY OF CAST IRON. 


the molten metal from the main runner to the sow. 

At Fig. 31 are shown what are called “ runner sta¬ 
ples, ' ’ which are used to support the ‘ ‘ cutters, ’ ’ as seen 
at Nos. 1, 2, 3, 4, 5, and 6, Figs. 24 and 28, also in the 
perspective view of the main runner seen in Fig. 34. 
As each pig bed fills up, the cutters stop the flow of 
metal, permitting it to flow into the adjoining bed as 
above described. When half of the beds are about 
poured off, slag then commences to come out with the 
iron at the notch-hole. To prevent the slag from pass¬ 
ing down the runner to the pig beds, a “ skimmer 
plate,” seen at I, Fig. 24, is knocked down to about the 
depth shown and then some sand is thrown against it 
on the side at K. By ramming this sand, the opening 
below the lower edge of the skimmer plate I and the 
bottom of the runner can be decreased at will, so that 
only iron may pass beyond the skimmer plate and its 
flow may be regulated. The slag is let run out at the 
“ slag runner” shown at the dotted lines K, Fig. 24. 
The slag running out of the tap-hole at every cast is 
considerable; often for every ten tons of iron there 
may be two tons of slag. 

After the pigs are cast they must be broken. This 
constitutes the most laborious work about a furnace. 
Before starting to break the pigs, which is not done 
until they have solidified sufficiently to not “ bleed,” 
sand to a depth of about ^ inch is thrown over their 
surface. Two or three men wearing wooden soles 
about i x /2 inches thick attached to their shoes, now 
start at the first poured bed with pointed i^-inch 
bars about six feet long. By inserting the point of 
the bar between the pigs at the end furthest from 
the “sow,” they are readily broken loose from the 


MOULDING AND CASTING PIG IRON, ETC. 107 

sow. After the pigs are all separated, the sow is then 
broken by taking the ends of the pigs of the next 
row as a rest to pry the sow lip; if not broken by 
being lifted, a sledge is then used. When two to 
three men will separate about five hundred pigs and 
break about eighteen sows in several pieces in about a 
half-hour’s time and not seem in any hurry, it is safe 
to conclude that the work is done by a very commend¬ 
able system. 

After the pigs and sows are broken as above de¬ 
scribed, a stream of water is turned on to cool them off 
so that they can be handled and removed from the cast¬ 
ing house in time to permit the bed being re-moulded 
for its next turn in casting. This, in a furnace of the 
size as seen on page 49, making five taps every 24 
hours, leaves but about three hours for the “ iron car¬ 
riers ’ ’ to break up and load on buggies, for removal 
from casting house, about 40 tons of pig metal. To 
permit a buggy being brought close to the iron to be 
loaded, a wooden track fastened together in sections of 
about 10 feet is laid down on the casting floor to any 
length or turn desired. There are always two floors to 
a casting house, so as to permit one being molded and 
got ready for a cast while the other is being relieved of 
its pig metal and wet down ready for molding. A cast¬ 
ing house, as it generally appears about one-half hour 
before casting time, is seen in Fig. 34. The keeper 
seen standing by the notch of the furnace has 
his runner made with the runner staples and cutters 
in position. The man on the right, at the lower end 
of the runner, is shown just finishing the ramming 
of the last bed of pigs. To afford an idea of cast¬ 
ing, ’the first man on the left of the main runner is 


108 METALLURGY OF CAST IRON. 

shown standing ready to drive the cutter into the 
runner to stop the metal from flowing to the first bed. 
The second man seen on the left stands ready to ravel 
out the branch runner to the pig bed. The third man 
having a pole in his hand is supposed to be breaking 
up the crust of slush formed in the front of the metal 
as it first comes down the main runner. These last 
three men are simply placed in position shown to illus¬ 
trate their work, as if metal had been actually running 
down the runner as above described. To those never 
having seen a casting house, Fig. 34 should give a 
general idea of the methods employed for moulding 
and casting pig metal. 

Moulders are often employed at a furnace to make 

moulds, open and closed, to be poured with metal as it 
comes down the runner. How to regulate the flow 
so as to stop it as soon as the mould is filled is a trick 
often worth knowing for application even in a foun¬ 
dry. At Fig. 26 is seen a section, through A B of Fig. 
27. The moulds shown are supposed to be “ open 
sand ’ ’ plates, which should be as uniform in thick¬ 
ness as possible. By the plan shown, if the metal is 
as “ hot as is generally obtained, the plates can be 
made not to vary over yi inch in thickness, which is 
as close as a founder can generally run them where he 
has metal in a ladle supposed to be under perfect con¬ 
trol. To explain this principle, attention is first 
called to Fig. 25, which is a section of the main run¬ 
ner. At the dotted lines N and M is seen the depth 
to which the branch runners connecting the sow and 
main runner are generally made and which are sup¬ 
posed to drain all the metal from the main runner until 
‘ ‘ cut off ” by the ‘ ‘ cutters ” B, as seen in Figs. 24 and 


MOULDING AND CASTING PIG IRON, ETC. 


IO9 

28. By making a comparison in the depth of the open¬ 
ing P with M and N, Fig. 25, it will be seen that the 
opening at P could not deliver any metal unless the iron 
was raised in the runner to its level, and the chances 
are, in the general working, that the iron in the main 
runner might never reach the bottom of the opening 
at P. But to compel it to do so, a stopper composed 
of slag, chilled on the end of a one-inch iron rod, as 
seen at S, Figs. 25 and 27, is placed in the main run¬ 
ner to impede the flow of the metal. This action raises 
the height of the metal in the runner so as to make it 
flow out at P, and the moment the stopper S is lifted, 
the metal is lowered below the level of this outlet, 
and hence instantly ceases to flow into any mould 
which may be run by such a plan. This last method 
governs well the actions of the main runner in filling 
moulds; but there is still another point to guard 
against where two or more castings are poured from 
such a branch runner, and this is the tendency of one 
mould to fill before another, and hence produce castings 
thicker or thinner than might be desired. To regu¬ 
late this point, a portion of the edge of the mould is 
cut away to the thickness desired, as seen at B in the 
plan view, Fig. 27, and also in the section A B, Fig. 
26. Such moulds being generally raised above the 
level of the floor, it can be readily conceived that any 
overflow at the points B will be received at a lower 
level than that of the castings, hence the difficulty, with 
good metal, of obtaining such castings thicker than they 
might be desired. It may be well to state that out¬ 
lets, such as at P, should be made well up towards the 
upper end of the main runner, so that when the stop¬ 
per V S is lifted the metal will have a good chance to 


iio 


METALLURGY OF CAST IRON. 


run down the runner and fill the pig beds through 
lower outlets, as at N and M. The dotted lines O O, 
in Figs. 24 and 25, are supposed to be level, and the 
angle of the main runner shows the incline from this 
level line. 

A plan of the pattern is seen at T, Fig. 33. The recess 
at A is to assist the pigs being broken in two pieces 
when cold, and the formation as seen at B where the 
pig and sow join to make their separation at this point 
easy when breaking the iron after a cast. The same 
number of patterns are used as there are pigs to be 
moulded in a bed. A good method of forming these 
patterns is by a combination of sheet steel and wood. 
The steel which forms the outside, as shown by the 
heavy black line at P, is about inch thick, and formed 
to shape over an iron block before the wood is secured, 
as shown at V V and at S, the latter being a 1 % -inch 
piece of hard wood, secured by wood screws passing 
through the steel at the upper edge of every 4 inches 
into the wood board. To secure the pattern at its end, 
a ^-inch rod passes clear through each end and is riv¬ 
eted. This method makes a very light pattern, and 
one which will last for years, and discounts a dozen 
times over the old plan of making all-wooden patterns, 
which are still used by some. The principle involved 
in the construction of these patterns is one the founder 
and patternmaker might often well utilize. The sow 
pattern is made of a continuous stick of timber, having 
one side at T faced with a sheet of ■}£ -inch steel, so as 
to prevent warping of the pattern. There is also a piece 
of iron ^ x 2 inches set in and screwed down on the 
top surface of the sow pattern, as seen at K, for the 
purpose of leveling; as constant friction of a level on 


Moulding and casting pig iron, etc. 


i n 


the surface of wood would cause it to splinter and be 
uneven for leveling purposes. 

In using these patterns and bedding them in the 
floor, there is no heavy sledge hammer used to settle 
them, as a moulder generally does with his patterns. 
In fact, no sledge or hammer is used on them, the only 
thing leveled is the sow; if one end is high, the pat¬ 
tern may be lifted and sand scraped away from under 
it, or the low end maybe raised and sand tucked under 
it by means of the handle end of the shovel or a push of 
the foot. The sow having been leveled, the pig patterns 
are then laid down on the floor, which has previously 
been leveled off with a shovel as near as the eye can 
judge, and which is generally done truer than many 
of our moulders are capable of doing. When the pat¬ 
terns are all in place, sand “ riddled through the 
shovel” fills up the space between them, and a man 
with a rammer 12 inches long, as seen at the right, in 
Figs. 32 and 34, rams the sand between the patterns. 
After going over with this rammer once, sand is then 
shoveled over the bed, and a flat scraper 18 inches long 
scrapes the sand off level with the top surface of the 
patterns, which is all the packing or sleeking the sur¬ 
face or joint of the bed receives. Sand having been 
pushed with the back of the scraper to raise a mound 
of sand between the pig beds to prevent metal flowing 
over, the sow pattern is now drawn out by means of 
the lifting iron seen at D, Fig. 33. The sow having 
been removed, the pig patterns are then drawn out by 
first raising one end with the hand in the recess at the 
end R until they can be lifted by the center, when 
they are tossed on to the next bed ready to be set up 
for another filling of sand. Some moulders might feel 


112 METALLURGY OF CAST IRON. 

like asking, “Was there no swab used?” No, the 
wetting the joint receives is as if by chance the fellow 
on the other side of the house wetting down the floor 
should, in turning around carelessly, throw a stream 
of water over the joint. I do not wish to be under- 
stood as saying that because pigs can be made with 
such apparent carelessness, rapidity and little labor, 
the moulder should do the same in making “ open 
sand” work in a foundry; but nevertheless the prin¬ 
ciples involved should be studied by those moulders 
who require a whole hour to make about a dozen cast 
“ gaggers. ’ ’ 

ilodern moulding and casting of pig metal involve 
points which the founder can often utilize to advan¬ 
tage. The principle involved in using open grades of 
sand and having deep floors to afford a chance for ex¬ 
cessive moisture or water to pass downward, is one 
the founder having much “open sand” work to do 
can often well adopt. How frequently do we find 
moulders making “ open sand ” castings that “ kick ” 
and “ bubble ” in such a manner that, when the cast¬ 
ings come out, it is a question whether they came 
from a foundry or furnace “boil.” Drop close grades 
of moulding sand and adopt a sharp open sand, and 
use regular moulding sand only where the metal 
from the pouring basin strikes the flat surface of the 
mould, and the trouble as above described with “open 
sand” work in a foundry will decrease. 


CHAPTER XIV. 


CHILLED OR SANDLESS PIG IRON AND 

ITS ADVANTAGES. 

Casting pig iron in sand moulds is objectionable in 

many ways. To overcome these objections there have, 
since 1896, been several different methods adopted for 
casting the metal in chills instead of sand moulds, aside 
from the practice of casting in chills placed in the floor 
of a casting house, which some follow, especially as 
used for making basic pig iron. The principle involved 
in the latest improvement lies in having iron moulds, 
the form of pigs arranged on a movable table, etc., so 
that the metal first running from the furnace into 
ladles can be poured into the pig moulds; after which, 
by self-dumping devices, they may carry the pig 
iron into' cars ready for shipment. This saves the 
arduous labor of breaking the hot pigs and sows in the 
casting house and then handling them by hand to 
remove the pigs from the casting floors, and, aside 
from this, produces pigs which do not require break¬ 
ing, and is also free of sand and scale, the advantages 
of which are stated on the next page. 

There are several machines on the market, among 
which are those patented by Mr. E. A. Uehling, Mr. R. 
W. Davies, and Mr. H. R. Geer. A large number of 
furnaces are now using these different machines, and 
it is probable that many more will do so in the future. 


I 14 METALLURGY OF CAST IRON. 

The first edition of this work recommended the adop¬ 
tion of these easting machines, and all that was said in 
their favor has been verified by practice. 

The economy and advantage to be obtained by using 
chilled or sandless pig metal in foundries, steel works, 
etc., may be stated as follows: First, being a harder 
iron by reason of its chill or density, which holds the 
carbon more' in a combined form, as well as having 
pigs free of sand (silica), less time and fuel will be 
required to melt it. Second, the pig being sandless 
there will be less fluxing needed and less slag to take 
care of in large heats; this will also give a cleaner iron 
to pour moulds, whether for small or large heats. 
Third, being a chilled iron or more dense it will give 
a softer re-melt than if the furnace iron had been cast 
in sand moulds. This is a discovery made by the 
author, the details of which are found on page 338. 
Fourth, by pouring furnace metal from ladles, better 
mixed metal will be obtained in a car or cast of pig iron 
than by casting pigs in sand moulds. The value of this 
will be better understood by reading Chapter XVIII. 

Some founders, understanding by experience the 
value of having the iron charged into cupolas as free 
of sand, scale, or dirt as possible, go to the labor of 
tumbling all their gates, etc. Could such founders 
also secure their pig iron free of sand, they could derive 
still greater benefit by having clean iron to re-melt and 
pour into their castings. What sandless pig the author 
has used proved much preferable to sand pigs in several 
ways. This experience is endorsed by others, as can be 
seen by the following extracts from a few letters which he 
obtained during 1899 by courtesy of Mr. Edgar S. Cook, 
president of the Warwick Iron Co. of Pottstown, Pa. 


ADVANTAGES OF CHILLED OR SANDLESS PIG IRON. 115 

A stove manufacturer says: “ From the experience 
we have had we believe, thus far, that you can be sure 
there is one foundryman who does not fear the sandless 
Pig-" 

A prominent tool builder says: “We have tried the 
sandless iron and find it very nice. You may ship 
more on our orders. ” 

The head of a large ship-building concern says: “ I 
am pleased to say that your sandless pig is very satis¬ 
factory. I hope hereafter you will always ship me sand¬ 
less pig, it saves a good bit of trouble in the cupola.” 

A stove works says: “We have watched the results 
very carefully thus far, and find it most satisfactory. 
The only objection we have to the ‘ sandless iron ’ is 
that the pigs are too heavy and hard to break. Our 
cupola men can hardly handle them, as our facilities are 
such that the short, heavy pigs of the sandless iron cannot 
be broken, otherwise we are very much pleased with it. ’ ’ 

With reference to the complaint that sandless pigs 
are too large, this has been remedied in some of the 
machines so as to make the pigs of a convenient size 
for all cupolas over thirty inches inside diameter. It 
is not to be understood that all chilled or sandless pig 
will show white fractures should they be broken; this 
will largely depend upon the percentage of silicon and 
sulphur in the iron. Iron above 1.20 silicon and not 
over .04 in sulphur, with manganese below 1.25, will 
rarely show any chill, but, of course, be more dense or 
higher in combined carbon than if the same iron was 
cast in sand moulds. -Cuts of sand and chilled cast 
pig are shown in Figs. 35 and 36. These cuts were 
originally presented by Mr. Alfred Ladd Colby in the 
Iron Trade Review, June 13, 1901. 


METALLURGY OF CAST IRON. 


I 16 



As far as saving of labor and other expenses is con¬ 
cerned, the casting machines do not prove as advan¬ 
tageous as some other 
improvements in mak¬ 
ing pig iron; however, 
they dispense with the 
hardest labor and give 
a product that, in 
many cases, is much 
more desirable than 
sand pig. For this 
reason their use will 
continue to increase, 
but probably will not 
do away with sand 
pigs entirely; at least, 
most of the furnaces not using floor chills will be required 
to keep sand beds in order to take care of their metal 


FIG. 35. — SAND CAST PIG. 



FIG. 36. — MACHINE CAST PIG IRON. 


in case of accidents to the machine. For this and 
other reasons the author has thought it well to retain, in 
this revision, the information in the preceding chapter. 




CHAPTER XV. 


UTILITY OF DIRECT METAL FOR 

FOUNDING. 

In the first days of founding, castings were made 
from metal taken directly from the furnace making 
the iron. The difficulty and uncertainty of obtaining 
the grade of iron desired and the fluidity necessary to 
insure good work, as well as the advantage of having 
metal at the time best suited to the founder’s needs, 
gave rise to the origination of the cupola to re-melt 
iron. Had the furnace advanced anywhere near the 
degree in assuring a uniformity of “grade” that it 
has in increasing its output many more castings would 
now be made direct from furnace iron. While some 
may question the ability of the furnace to ever achieve 
any better results in always obtaining a uniformity of 
product, competition may strongly influence an effort 
for improvement in this direction. Aside from the 
above evil is that of the trouble caused by the “ kish ” 
found with some metals that throw out graphite exces¬ 
sively. Often after a furnace “ cast ” of Foundry or 
Bessemer the floor of the house will be covered with 
“ kish,” which resembles in appearance flakes of silver 
lead or plumbago, and are like the flakes of carbon 
so often found between grains of pig metal and cast¬ 
ings. It can be removed from fractures by means of 
a stiff brush or rubbing. 


Il8 METALLURGY OF CAST IRON. 

The evils to be expected from metal possessing much 
“kish” are mainly in “cold shuts,” spongy, porous 
spots in castings, or the separation of the grains of 
the metal at places where “kish” is confined. One 
might as well try to make a union of oil and water as 
of kish and cast iron. Were it possible to collect or 
skim off all the “ kish ” created on top of direct metal, 
little damage might be expected; but this is not prac¬ 
tical, as the “ kish ” keeps rising to the surface as long 
as the metal is in a fairly fluid condition. Appliances 
have been invented with a view to collect the “ kish ’ ’ 
in pouring runners, etc., before the metal would enter 
the moulds, but these have proven of little value. It 
may be said thar metal possessing much “kish” is 
unfit for pouring many lines of castings. 

Direct metal free of “ kish ” can make very good 
castings, and for some classes of work might often 
prove more desirable than cupola iron, as less sulphur 
can be obtained in direct metal than with iron re- 
melted. Iron cannot be re-melted in the cupola, 
with coke or coal, without increasing its sulphur 
from .02 to .06 points. The re-melting of pig metal 
entirely destroys the ‘ ‘ kish ’ ’ that appears in direct 
metal. 

The life and fluidity of direct metal, compared 
to cupola iron, are qualities some will question. If 
a furnace is working properly, its product will compare 
very favorably, as regards these qualities, with cupola 
iron. The author has seen hotter iron from a furnace 
than is generally obtained from cupolas that hold its 
life or fluidity exceptionally long. In fact, the author 
is of the opinion that direct metal can have such an 
initial heat imparted to it as to create a much greater 


UTILITY OF DIRECT METAL FOR FOUNDING. 


1 r 9 

life to the fluidity of the metal than can be obtained in 
re-melted iron. 

To utilize direct metal, some have thought it would 
be a good plan, in order to overcome the difficulty 
from ‘ 1 kish ’ ’ and obtain a more uniform product, to 
first pour the metal coming from two or more furnaces 
into a large receiver or reservoir so arranged as to 
closely confine from 50 to 100 tons of iron, one idea 
being that if the metal should have “ kish ” in one fur¬ 
nace, another would be free of it to mix with it, and 
hence an average could be obtained which would be 
sufficiently free from “kish” to obviate any defects 
in the casting. The information which the writer has 
obtained as to the success of this plan is not very 
favorable. The difficulty found consisted in the metal 
losing too much fluidity and life by the extra handling 
and detention of the metal in the fluid state. Where 
work is very massive, not requiring good “ hot iron,” 
this reservoir method may be of much value; but the 
difference which exists in the cost of direct metal and 
cupola iron does not warrant any very great chances 
being taken in losing castings on account of the fluidity 
and uniformity of a “grade” not being as desired. 
However, for castings like ingot moulds and pipes, 
“ direct metal ” in days of close margins may com¬ 
mand attention in some cases. * 

It is no uncommon thing for us in our foundry to 
make small castings with direct metal carried by three 
men in a “ bull ladle,” taken from a furnace close by 
us. The plan which we adopt to obtain such small 
bodies of metal is simply to catch the metal with a 
“hand ladle” by dipping the iron out of the main 
runner as it flows to the pigs and pouring it into a 

*At the close of 1903 we commenced pouring all our castings with direct 
metal, and are now (Aug. 1904) using about 150 tons daily with the intention of 
increasing its use up to 600 tons or more every 24 hours when the steel busi¬ 
ness improves. 



I 20 


METALLURGY OF CAST IRON. 


“ bull ladle. ” We have made very good castings by 
this plan. We have also taken “ direct metal ” in crane 
ladles by having a car run on a track sunk sufficiently 
below the main runner to receive the metal from a 
branch runner extending beyond the casting house. 
With iron containing silicon under i.oo, manganese up 
to i.oo, the higher the better, and sulphur above .03, it is 
rare that any kish is seen, and when such direct metal can 
be obtained very good castings can be produced. Of 
course, with a low silicon and high sulphur iron it is 
not to be expected that any work less than half an 
inch thick, requiring any fine finishing in the machine 
shop, can be satisfactorily obtained, but for bodies 
over the above thickness very little trouble should be 
experienced, as long as the metal does not get over one 
per cent, in silicon and keeps up in manganese and sul¬ 
phur.* As seen by study of Chapter XVII., it is the 
changeable percentages of silicon and sulphur which, as 
a rule, alter the grade in the product of a furnace when 
running on one kind of ore, flux, and fuel. Late 
improvements and a better understanding of furnace 
work is doing much to lessen irregularity in the per¬ 
centages of silicon and sulphur. In fact, some 
furnacemen have so mastered the art of making iron 
that they can run weeks at a time without varying 30 
per cent, in silicon or three points in sulphur, when 
making iron having less than 1.25 silicon. It is with 
silicon above 1.50 per cent.— also in very hot weather, 
as shown by Chapter XVII.— that the greatest diffi¬ 
culty is experienced, at present, in regularly obtaining 
a uniform grade of pig metal. 

'•Direct meial of the same analysis as cupola or remelted iron is the softest 
iron and has another peculiarity of having the greatest shrinkago in soft 
grades, 



CHAPTER XVI. 


BANKING FURNACES AND CUPOLAS. 

The principle involved in “banking” is simply to 
do everything possible to prevent air finding access 
through the body of a furnace to the fuel, so as to 
stop rapid combustion and sustain the fire only in a 
dormant state until it is found desirable to again 
“ blow in ” the furnace. This is similar in principle 
to the. practice of smothering a fire in a stove over 
night so that next morning little labor or fuel would 
be required to start a good fire and provide a quick 
breakfast. The old plan of “banking” a furnace in¬ 
volves considerable labor and expense. One system 
followed is to encircle the furnace with a curbing of 
plates bolted together, or planks stood on end, pro¬ 
jecting 2 or 3 feet above the tuyeres, the planks be¬ 
ing held together by means of hemp or wire ropes, 
the space between the furnace and the curbing being 
about 2 feet, which is filled up with a close grade of 
sand. Before encircling the furnace with this curb¬ 
ing, the slag pipe and the tuyeres are all taken out 
and all their pipe connections removed. (The pipe 
connections to the coolers are not disturbed, as water 
is left on them during the time of “banking. ”) After 
this the tuyere holes in the brickwork, etc., are filled 


I 22 


METALLURGY OF CAST IRON. 


with clay. This system makes it almost impossible 
for any air to find access to fuel in the hearth, where 
so many openings for tuyeres, etc., would leave crev¬ 
ices for air to enter. The stack portion being practi¬ 
cally a solid body enclosed by a tight shell of iron, no 
attention is given to it; so also with the bell and hop¬ 
per at the top of the furnace, as some ventilation is 
desirable at the top to allow any excess of gas to free¬ 
ly escape. For this purpose, the “bleeder” pipe valve 
can be forced open, as in no case is the “down comer” 
valve opened. From this “bleeder” the state of the 
fire in the furnace can also be fairly judged. Nearly 
all furnacemen differ somewhat in their methods of 
“banking.” At the present day many have aban¬ 
doned the practice of encircling a furnace with a 
curbing above described, and after removal of the 
tuyeres and pipes they simply pack all holes and crev¬ 
ices with clay rammed tightly in place, and then oc¬ 
casionally wash the outside of the lining or brick¬ 
work, which is exposed to the air, with a thick coat 
of clay wash, thus closing up all crevices or pores 
which might admit air to the fuel. This plan, while 
costing much less than the curbing system, has been 
found sufficiently effective to answer all purposes. In 
preparing the furnace for being “banked,” it is essen¬ 
tial to free it as much as possible from its regular 
charges, and any liquid metal which may be in the 
hearth below the tapping hole. 

To liberate the liquid metal all that is possible from 
the bed of the furnace, a hole is sometimes made 
from one to two feet below the level of the top of the 
regular tapping hole, which permits the metal to run 
out into an excavation in the ground in the form 


“banking” furnaces and cupolas. 123 

of a long runner, so that what flows out below the 
level of the tap-hole can be broken up. This plan is 
one adopted for “blowing-out” as well as “ banking.” 
As will be seen by Fig. 19, page 93, there are 
often very large bodies of metal below the tap hole. 
Even by the plan just described these are rarely ever 
all drained from a furnace, always leaving some to 
solidify that will have to be brought back to a liquid 
state when the furnace is “ blown in,” requiring as a 
general thing but a few days. 

The first move in preparing to “bank” a furnace is 
to discontinue its charges of ore and lime in the regu¬ 
lar way and to admit chiefly fuel, in order to keep the 
furnace filled, occasionally dumping a little ore and 
lime to divide the fuel and to destroy the union of a 
solid combustible body of fuel and thereby assist in 
smothering combustion. As soon as it is found that 
the last regular charge of ore, lime and coke has 
passed the level of the tuyeres, the furnace is tapped 
and an extra pressure of blast applied so as to force 
out all metal possible. This done, the blast is shut 
off and the “ banking ” operation commenced. When 
this is completed the furnace is filled up with fuel, etc., 
as above described, and in some cases the surface of the 
last charge is covered over with fine ore or loam sand 
to assist in shutting off draft, in which state the fur¬ 
nace is left standing. As a general thing, wherever 
sand can be used for banking, it is preferable to clay, 
as the latter is apt to crack in drying and leave crevices 
whereby air can find access to the fire to excite com¬ 
bustion. 

In some cases the fire may lie dormant in a good 
condition for six months or more without any renewal 


124 


METALLURGY OF CAST IRON. 


of fuel, but this is seldom done. If, after three or six 
months of banking, it is found that conditions of trade, 
etc., will not demand “blowing in,” as anticipated 
when first banking the furnace, the fires will often be 
allowed to die out, in order to make preparations for 
“shoveling out,” so as to discover if a furnace re¬ 
quires re-lining in parts or as a whole. 

A good illustration of the extent to which banking a 
furnace may be carried is that conducted under the 
able management of Mr. C. I. Rader, during the years 
1 893-95, at the Paxto^ "Furnace, Harrisburgh, Pa. 
Furnace No. 1 at tnis place was ua^-ed August, 1893, 
and not opened until June, 1895, a period of one year 
and ten months, at which time the furnace was found 
in a condition to be successfully “ blown in.” Mr. 
Rader says a light ore burden and half coke and an¬ 
thracite were used in banking down the furnace, and 
the top covered with a layer of fine ore. This is the 
longest period of successful “banking” of which the 
author has any record. 

When “ blowing in ” a “ banked furnace,” the first 

operation is to clean out the tuyere holes, etc., of their 
clay and sand packing, after which the refuse and dead 
ash in the furnace are pulled and shoveled out through 
the tuyere openings and slag holes, so far as possible. 
This done, the tuyeres are replaced and their water and 
blast connections completed. A heavy bed of fuel is 
now charged, after which charges of ore, lime and fuel 
are delivered into the furnace. The burden of ore 
and lime is gradually increased in weight in the first 
charges until several are delivered, when the regular 
burden is then charged on. The blast being on, the 
furnace is again in condition to make iron. For the 



BANKING 


FURNACES AND CUPOLAS. 


I2 5 


< < 




first two “ casts” or day’s run a furnace is liable to 
work cold, which results in giving - a low-grade metal 
or iron high in sulphur and low in silicon. As a gen¬ 
eral thing, furnaces are compelled to use cold blast 
when “blowing in,” for the reason that there is no 
gas to make the hot blast ovens operative until after a 
furnace becomes sufficiently heated to have gas pass 
down the “down-comer” to the ovens. A few plants, 
like that of the Carnegie Steel Co., having several 
furnaces connected or in close vicinity, can bring hot 
blast from other furnaces until the “blown in” furnace 
gets under way. Where cold blast has to be used at 
the start, it takes much longer to get a high-grade 
iron than where hot blast can be obtained. With hot 
blast they may often, at the very first “ cast,” secure 
high grade iron, whereas with cold blast it may take 
a dozen “casts” or more to do so, and in either case, 
the largest output is not generally obtained until a 
furnace has been in blast from one to three months. 

Those founders inexperienced in furnace work 
can well imagine from the description here cited that 
although “banking” is a compromise to “blowing 
out,” which means a complete shut-down, the furnace 
manager is desirous of avoiding such manipulations so 
far as possible, as the expense is by no means light, 
and many sacrifices will generally be made in having 
capital lying idle in piles of pig iron in order to run a 
furnace steadily, rather than “ banking ” to await in¬ 
crease of orders or a demand for their product. If 
furnacemen have any assurance that they will not 
“ blow in ” after three months’ “ banking,” they will 
generally “blow out,” as the accumulation of ash and 
dirt from a furnace banked to exceed three months 


126 


METALLURGY OF CAST IRON. 


is such as to be very apt to make it difficult to get 
a furnace working well for a week or more after it is 
“blown in.” 

Banking is generally done in cases where a shut¬ 
down is thought to be only temporary. If a furnace 
“ blows out,” which means a clear shut-down, nearly 
the same amount of fuel and lime is often charged to 
follow the stock down as if the furnace was being 
“banked.” This is done so as to burden the blast 
and keep the heat or flame of the furnace from escaping 
and thus better reduce the stock of ore to metal and 
also cause less heat to affect the upper lining as well 
as the bell and hopper from melting, and makes a 
cleaner furnace when “ shoveled out. ” There are a 
few that will “ blow out ” a furnace without covering 
the last charge of ore well with fuel and lime, but 
this plan is not considered good and safe furnace 
practice. 

In “blowing out” a furnace, the fuel used to follow 
the stock down can be largely saved, for as soon as the 
last tap of iron is made, and the blast shut off, the 
tuyeres P, Fig. io, page 49, can be all pulled out and 
the incandescent fuel raked out on to the ground floor, 
where with a hose, water will soon dampen the fire in 
the fuel, which will be found to be but little burned, 
so that it can be used over again. After the fuel is 
all pulled out level with the tuyere, water can then be 
thrown by a hose to dampen the fire in the hearth, so 
that in six to ten hours after the blast is stopped all 
fire can be extinguished. 

Where banking a cupola might be thought of, as re¬ 
ferred to at the close of this paper, it is generally well 
to have a charge of fuel follow the last charge of iron, 


FURNACES AND CUPOLAS. 


I 27 


“ BANKING 

as this would better assist closing off all draft than 
were the last charge all iron, as a fine dust fuel, ore, 
etc., could be used on the surface to close up all cavi¬ 
ties without calling for enough to cause injury, as 
would be the case with fine stock used to close up the 
cavities between pieces of iron, instead of fuel. 

The principle involved in “ banking” a furnace is 
one that has to a slight degree been practiced by some 
founders, as is seen in “American Foundry Practice,” 
page 301. The author is so sanguine that the prin¬ 
ciples involved in banking are practical for application 
in cupola work, that he lately remodeled one of his 
cupolas with a view of experimenting to find 
out how many heats he could run without drop¬ 
ping the bottom. At this writing conditions in our 
shop work have not permitted giving it a trial, the 
reason for which lies in the fact that the cupola which 
was prepared for this experiment was not large enough 
to run the heats demanded. The plans followed in re¬ 
modeling this cupola consist simply in making all 
tuyere connections air-tight, raising the spout so as to 
permit of from two to four inches of a heavier sand 
bottom, also in providing a double slide arrangement 
facing the tuyere openings which, when both were 
closed, left a space between them to be filled with 
loose'sand that could be readily removed by a little 
slide pocket in the bottom of the sand space. These 
two factors, combined with an arrangement to posi¬ 
tively shut off the admission of any air where the 
main blast-pipe is connected with the wind-box, com¬ 
pleted the arrangements. With this device it is the 
intention, after the first heat has been run off, if not 
a large one, to thoroughly melt down any iron that 


128 


METALLURGY OF CAST IRON. 


may be in the cupola, after which the breast will be 
opened and all dead ash and refuse lying in the 
“bed” will be raked out. After all dead material has 
been thus cleaned out, the breast will be firmly sealed 
up with tightly rammed sand, and all tuyere connec¬ 
tions, etc., closed as above described. A little extra fuel 
being now put in and the top charging door closely 
sealed, the cupola will be allowed to stand in this con¬ 
dition until time to charge for the next heat, when the 
“bed” will be “ replenished,” the cupola re-charged, 
and, after the breast has been replaced, the heat pro¬ 
ceeded with as usual. How many times this opera¬ 
tion can be repeated without “.dropping the bottom ” 
can only be told by practice. In endeavoring to follow 
such a practice the management of the cupola must be 
in intelligent hands, as it can be readily seen that to 
charge a cupola ignorantly or carelessly, as is often 
done, would result in leaving iron at a level with the 
tuyeres, or all on one side of the cupola, so that it 
could not be melted at the end of a heat. These ideas 
are not presented with the expectation that all found¬ 
ers are going to drop their present methods to adopt 
the plans outlined; they are simply offered as sugges¬ 
tions to evolve ideas which may favor the inauguration 
of new practices that to-day might seem absurd and 
impracticable. 

John C. Knoeppel, of the Buffalo Forge Co., Buf¬ 
falo, N. Y., recently related to the author an experi¬ 
ence in banking a cupola, which may often prove of 
benefit. In brief it is as follows: The blast had just 
been started and the iron was not yet down, when an 
accident occurred to the machinery, stopping the 
blast. As the damage could not be repaired within 


“banking’’ furnaces and cupolas. 129 

the lapse of many hours, Mr. Knoeppel simply closed 
all air openings tightly with clay and sand, and cov¬ 
ered the top of the stock at the charging door with 
fine dust coke. When the blast was started, about 
sixteen hours after the shut-down, the melting went 
on in good shape, as in the usual practice. This was 
done in a cupola of about 56 inches inside diameter. 
One factor assisting to make Mr. Knoeppel’s plan so 
successful was the fact of the iron not having started^ 
to melt when the break-down occurred. Mr. Knoep¬ 
pel’s experience, combined with that recited by the 
author in “American Foundry Practice,’’ above noted, 
may suggest expedients which may often be profitably 
adopted. 


CHAPTER XVII. 


CONSTANT AND CHANGEABLE METAL¬ 
LOIDS IN MAKING IRON. 

» 

If, in making iron, all the metalloids remained fairly 
constant, not varying in their percentage one cast 
from another, we could obtain a uniform product and 
have no such thing as different grades of iron from like 
mixtures of ore, fuel, and flux. But this condition 
does not exist; instead, we find that a furnace, at the 
present state of advancement, seldom makes two casts 
of iron exactly alike in analysis or grade from the 
same mixtures of like ores, fuels, and fluxes. The 
elements that vary the most and effect the greatest 
change in the grade or the carbons of iron are silicon 
and sulphur. A furnaceman can be most particular 
and have all conditions alike as far as lies in his power, 
but for all this he may have some casts which will 
differ widely in silicon and sulphur contents, espe¬ 
cially when making iron over 1.50 silicon and in all 
grades during very hot weather. It is true there will 
be changes in the total carbon, manganese, and phos¬ 
phorus, but these rarely cause radical changes in the 
grade of an iron coming from like mixtures. Some 
experiences on this latter point are related in Chapter 
XVIII., page 136. It is to be remembered that the 
author is not claiming that manganese and phosphorus 


CONSTANT AND CHANGEABLE METALLOIDS, ETC. 131 

\ 

cannot effect a change in the grade of an iron. Varia¬ 
tions of either of these two elements can change the 
grade similar as variations in silicon or sulphur, but we 
must look to the furnaceman in preparing his mixtures 
of ores, etc., when making iron. If he desires an iron 
. high, medium, or low in manganese or phosphorus, he 
can generally obtain it so evenly, in iron below 3.00 
per cent, silicon, as not to affect in a practical way the 
grade of the iron which he desires to obtain, as long 
as the furnace uses the same ores, fuel, and fluxes. 
On the other hand, the silicon and sulphur may vary 
considerably at times. However, future advancement 
in obtaining more uniform temperatures and distri¬ 
bution of blast in a furnace, which is now being grad¬ 
ually secured by some, will bring about improvement 
in this line. Nevertheless, silicon and sulphur will 
always be the metalloids which will most largely 
change the grade of iron to a greater or less degree 
where the same ores, fluxes, and fuels are used. 

Changes in the total carbon. It is thought by some 
furnacemen that the higher the temperature, and the 
more slowly the ore passes down in its reduction to 
iron, to the hearth of a furnace, the greater total carbon 
will be found in like irons. However, the author has 
failed to find where there were changes in total carbon, 
by the use of the same ores, etc., sufficient to radically 
change the grade of iron. 

Ores from the same mines or locality are liable to 
differ in their composition sufficiently to occasionally 
change the percentage of manganese and phosphorus, 
to some extent, in the same brand of iron. Never¬ 
theless, such changes would generally call for an 
alteration of about half of one per cent, in manganese 


132 


METALLURGY OF CAST IRON. 


or one-fifth to one-third per cent, of phosphorus to 
change the grade, similar as the alteration of one- 
quarter of one per cent, in silicon would do. The 
author believes that furnacemen will agree that it 
would be very rare to have such a variation as above 
in manganese and phosphorus, in irons made from ore 
that comes from one mine or locality. As there is a 
liability, on rare occasions, of manganese and phos¬ 
phorus varying to an effective degree from similar 
ores, and then again a change in the total carbon to 
alter the grade of an iron, it may often pay those who 
are manufacturing castings, where such changes as 
above would seriously affect their iron, to always have 
an analysis of the total carbon, manganese, and phos¬ 
phorus in connection with the silicon and sulphur. 
There is one thing to be remembered and that is, that 
a furnaceman has far less difficulty in obtaining a 
uniform grade when making low silicon irons, or that 
under 1.50, than above this percentage; and also that 
there is much more difficulty in obtaining a uniform 
grade in very hot weather, due to humidity of the air, 
than when the thermometer is below 85 degrees F. 
More on this point is seen in Chapters X. and XLV., 
pages 78 and 306. Furnacemen are finding that if 
they are not called upon to increase temperatures of 
blast over 1,000 degrees F. (some find it best to keep 
between 850 to 900 degrees F.), and have a good uni¬ 
form distribution of the blast, they can secure a 
more uniform product than otherwise. Largely for 
these reasons furnacemen prefer to run on low silicon 
iron. 

One is most impressed with the uncertainty of fur¬ 
nace workings when in urgent need of ten hundred 


CONSTANT AND CHANGEABLE METALLOIDS, ETC. I33 

tons or more of any certain grade of iron over 1.50 in 
silicon from a furnace that is trying to make it, and no 
stock of iron in that special furnace yard to draw from. 
Anybody placed in this position might soon be 
forced to realize by reason of waiting for the ship¬ 
ments they desired, that furnacemen cannot, as yet, 
always perfectly control a furnace to obtain the grade 
they desire at every cast. 


CHAPTER XVIII. 


SEGREGATION OF IRON AT FURNACE 

AND FOUNDRY. 

We often find a segregation of metalloids in pig iron, 

but rarely, if ever, in re-melted iron or castings. 
One peculiarity in this respect lies in the difference 
often found in the upper cast body or face of pig iron 
containing the highest sulphur, as shown by the fol¬ 
lowing four samples, Table 18: 


TABLE 1 8.— SEGREGATION OF SULPHUR IN PIG IRON. 



No. i. 

No. 2. 

No. 3. 

No. 4. 

Top. 

.117 

. .115 

.084 

•055 

Bottom. 

.083 

.094 

.070 

.047 


The above analysis shows that “ direct metal,” or 
iron coming from a blast furnace, tends to favor the 
escape of sulphur, but that owing to the top surface 
of the pig chilling so as to form a crust at an early 
stage of the solidification of the metal in the pig beds, 
the sulphur in rising to escape was caught and hence 
the higher sulphur found in the top body of the pig, 
as shown. 

Silicon also segregates in pig metal. Wherever pig 
iron shows soft gray spots, analysis will generally 
show these to be higher in silicon than the sur¬ 
rounding metal. Then again, it has been found that 
the first metal from a furnace is generally lower in 
silicon than that which flows afterward, in a manner 
often so uniform as to show that there is a gradual 
















SEGREGATION AT FURNACE AND FOUNDRY. 


T 35 


increase of silicon in the metal from the bottom up¬ 
wards as it lies in a furnace before being tapped. 

Variations in the working of a furnace make a rad¬ 
ical difference in diffusion of the metalloids silicon and 
sulphur, as can be seen by the following analyses, 
which the writer has also secured for this work through 
the courtesy of Mr. C. C. Jones, an able, experienced 
furnace manager, operating two furnaces at Sharps- 
ville, Pa. The pig beds are numbered in the following 
Table 19 according as they were cast, No. 1 being that 
farthest from the furnace, receiving the first iron and 
No. 6 the last: 


TABLE 19. —ANALYSES OF PIG BEDS IN A CHANGEABLE FURNACE. 



1 

2 

3 

4 

5 

6 

Silicon. 

.60 

.084 

.68 

.70 

.062 

I.OO 

1.25 

.042 

2.20 

Sulphur.. 

.071 

.050 

.027 



With the furnace normal the result was as follows : 


Silicon. 

2.18 

2.18 

2.22 

2.23 

.019 

2.25 

.019 

Sulphur. 

.021 

.021 

.02) 



The above analyses of the normal working of a fur¬ 
nace present the best uniform distribution of silicon 
and sulphur which has come Linder the writer’s notice. 
As this is a question of no little importance to the 
founder, attention is called to Table No. 20, on next 
page, showing the analyses of eight (8) different “casts’ ’ 
giving the silicon contents from the bottom upward, 
subscribed by Mr. H. Rubricius in Chemiken Zeitung 
and the Journal of the Iron and Steel Institute , No. 2 , 
1894. 

The exhibits treat only of silicon and sulphur. 
With regard to the segregation, etc., of phosphorus 
and manganese, the only experiments which the writer 
has observed are those by Mr. A. P. Bjerregaard, com- 






























i 3 6 


METALLURGY OF CAST IRON. 


mented upon in the Iron Age, November 30, 1895. He 
states his conclusions as follows: “There is often a 
slight variation in the amount of phosphorus and man¬ 
ganese in the different grades formed in the same 
‘ cast, ’ but so far, no regular occurring progression 
variation has been observed. At best, the difference 
is only a few hundredths of one per cent. ’’ The author 
could present several more tables showing uneven dis¬ 
tribution of silicon, etc., but those shown are sufficient 
to illustrate the necessity for reform in the lines advo¬ 
cated by the author. 

When the founder considers that a difference of one- 

TABLE 20 .—SILICON ANALYSES OF EIGHT CASTS. 


Test of pig iron. 

1st bed. 

*0 

V 

.a 

XI 

<N 

'O 

<U 

X) 

rO 

4th bed. 

'd 

V 

& 

*-) 

6th bed. 

7th bed. 

i east. 

L13 

I 15 

I - I 5 

1.19 

i -*3 

1.40 

1.42 

2 cast. 

1.3a 

1-44 

1 45 

1.60 

1.63 

1.72 

1.79 

3 cast. 

115 

i -34 

M 3 

1 57 

2 17 

2.18 

2 2) 

4 cast. 

1 29 

1.50 

1 -54 

1.66 

1.82 

1.84 

1.88 

5 cast. 

i -95 

2.09 

2.13 

2-45 

2 70 

2.72 

2.76 

6 cast. 

1.81 

1.83 

1.84 

1.86 

1.89 

2.16 

2 20 

7 cast. 

2 72 

2.74 

2.77 

2.79 

2.85 

2.88 

2.89 

8 cast. 

2.46 

2.48 

2.50 

2-53 

254 

2.58 

2.60 


quarter of one per cent, in silicon and a few hundredths 
of one per cent, in sulphur will seriously alter the 
“grade” of his mixture so as to either make his “cast” 
too soft or too hard, and may often cause him great 
trouble or loss in the castings produced, he should at 
once perceive that the uneven distribution of silicon 
and sulphur which occurs more or less in every “cast” 
of a furnace is a quality seriously affecting his inter¬ 
ests. Especially is this so, when he is aware that the 
one analysis which may be given is simply an average 
of the whole, generally taken from the two ends and 






























SEGREGATION OF IRON AT FURNACE AND FOUNDRY. 137 

middle of a cast,” and that a car of iron may come 
to him from a “ cast ” having one portion from one- 
half to one per cent, higher in silicon than another. 
This is fully verified by Mr. Rubricius’s table which 
shows that the two ends of a “ cast ” may vary one per 
cent, in silicon. Mr. Rubricius also states that *' not¬ 
withstanding the large number of experiments made, 
it was not possible to correlate the initial percentage of 
silicon and the rate of increase, as iron poor in silicon 
presents, in some cases, a large increase in silicon in 
the upper parts. This can only be due to the differ¬ 
ence in specific gravity between silicon and iron.” 

The uneven distribution of silicon and sulphur in 
pig metal is largely duer to conditions over which 
furnace managers have, as a rule, not perfect con¬ 
trol, while with castings the moulder or founder can, 
at will or through methods in casting, give rise to an 
ill diffusion of the carbons that could often be pre¬ 
vented were he only aware of the conditions which 
effect such results in castings. The moulder when 
turning out a casting having hard or soft spots often 
finds the word “ segregation ” very convenient to 
disguise evil effects of hard ramming, wet sands, or 
ill-vented moulds. When a mould has been properly 
made and the iron well mixed and melted hot and 
poured as it should be, there is generally little to fear, in 
a practical way, from segregation in castings that can 
be charged to the iron, aside from what effects degrees 
in cooling or casting in a chill can have in causing 
different proportions of combined or graphitic carbon 
A rammer should never be allowed to hit a pattern, as 
this causes a hard spot -on the mould which, in light 
castings, can change the character of the carbons or 


138 METALLURGY OF CAST IRON. 

the iron at that spot. And the same is to be said where 
the swab or ill ‘ ‘ tempered ’' sand causes one spot or 
portion of the mould to be different from another, or 
the venting - is inadequate for the free escape of gas or 
steam. Hard grades of iron are more liable to an ill 
diffusion of the carbons than soft grades, especially so 
where the former is melted or poured dull. Light 
castings are also much more liable to an ill diffusion of 
the state of the carbon than heavy castings. The 
above statements also give additional reasons why test 
bars as small as one-half inch square, or any having 
square corners, are not the best standards for making 
comparison of mixtures, etc. 

By re-melting pig iron we effect a mixing process in 
which the chemical constituents of the castings will be 
uniform unless they are distorted by means of dull 
iron, hard ramming, wet sands, ill venting, or ‘ ‘ chills, 
as above stated. The metalloids most liable to segre¬ 
gate are the carbons and silicon. Chiefly with the first 
named lie most of the phenomena which effect segrega¬ 
tion in castings, and which are defined simply by one 
part being higher in graphitic or combined carbon than 
another. Some have claimed the existence of “ sulphur 
spots ” in castings. With iron melted or poured dull 
these may exist, but with the reverse conditions the 
writer has reason to believe, from analyses which he 
has conducted, that sulphur will generally be found 
uniformly distributed throughout a casting that has 
not blown or from any cause been chilled. 


CHAPTER XIX. 


MIXING CASTS OF PIG IRON AT FUR¬ 
NACE AND FOUNDRY. 

A difference of one per cent, in silicon which can 
exist between the ends of a cast of pig iron, as shown 
in the last chapter, should cause any thoughtful person 
to perceive the wisdom of thoroughly mixing a furnace 
cast or pile of iron before it is charged into a cupola. 
This is where the most uniform results in obtaining an 
even grade of iron are desired in any special line of 
castings. As an example, if an ill-mixed cast of pig 
averaging 2.00 per cent, in silicon, with its extreme 
ends varying 1.00 in silicon, was charged without being 
mixed, one part of the iron charged would contain but 

1.50 of silicon while the other portion would contain 

2.50 silicon. It is impossible to expect uniform results 
in castings from such an ill-mixed cast or pile of iron. 
Some foundrymen, when first adopting chemistry in 
making mixtures of iron, have had just such experiences 
as the above, but, not knowing, it condemned the princi¬ 
ple of working by analysis, when, in truth, it was not 
chemistry that was at fault, but the evils of ill-mixing 
or ill-diffusion of the silicon in a cast or pile of iron 
and no attention having been paid to the question of 
mixing it thoroughly before it was charged into the 
cupola. The founder adopting chemistry must have 


140 


METALLURGY OF CAST IRON. 


his practice based upon correct principles, or he cannot 
expect the results he desires in making mixtures of 
iron. An ill-mixed cast of pig iron can, generally, 
mislead any founder in determining the cause of fail¬ 
ure to obtain the grade of iron he felt so confident of 
securing. 

A thorough mixing of a cast of pig iron is not a diffi¬ 
cult task; it requires but a recognition of its necessity, 
and means can be readily devised to accomplish the 
end. One plan, practicable of adoption by most 
furnaces, would be when loading cars for shipment to 
consumers to have every other buggy load, or pig if 
handled by men, placed at the opposite ends of the car. 
When the foundryman unloads the car he should follow 
the plan pursued in loading, which means to take a 
pig from each end of the car alternately and load onto 
buggies or in piles. By such a method a cast or car of 
iron should be pretty well mixed by the time it was 
charged into a cupola. 

Where a founder has yard room, a good plan is to 
load several cars of the iron closely alike in analysis, 
or for one mixture, on top of each other in a long pile, 
being careful to have each car load distributed evenly 
in height the whole length of the pile, and in taking 
the iron from the car take a pig from each end alter¬ 
nately as near as practicable. A pile of any certain 
grade or brand of this character can be made to hold 
six or more cars of iron, and then when using the iron 
from the piles it is taken from the two ends as 
uniformly as practicable. A little study of this method 
will show that drillings taken from four to six pieces 
of pig, pulled from a fair division of the two ends 
would, when thoroughly mixed and analyzed, give an 


MIXING CASTS OF PIG IRON AT FURNACE, ETC. 141 

analysis that would be a very close estimate of the 
silicon or other metalloids to be found in any such 
body of iron in that special grade, brand, or pile of iron. 

Very often the founder has not room to pile iron, or 

is compelled to use it direct from cars or small piles 
already in his yard. In such cases the different casts, 
or parts of such, could, after being mixed in loading it 
on buggies as described, be conveyed to the cupola 
stage and stacked in distinct piles according to varia¬ 
tions that exist in the percentages of silicon, etc. 
When charging the iron that amount necessary to 
make a mixture would be taken from the different piles 
in an alternate manner; this would insure a good 
mixing of the grades as they lay in the cupola. For 
an example, if an average of 1.90 in silicon was desired 
in a mixture, and the only iron that could be obtained 
were casts or piles containing 1.60 and 2.20 silicon, 
with sulphur about uniform, then each pile would be 
piled separately on the cupola stage and a pig taken 
from each pile alternately when charging the cupola. 
This is a plan which works well, providing a trusty 
man is in control of the charging. If such is not in 
command, there are times when this practice leaves a 
chance for error. Such can be brought about by new 
men, or old ones, making errors in sorting or placing 
the iron on the staging or in charging it into the 
cupola. 

A plan which avoids risks, wherever two or more 
grades must be used to obtain the average desired, as 
described in the last paragraph, is to have different 
brands or grades go to the stage at the same time on 
independent buggies, and then instead of piling each 
grade separately as is done in the above plan, they are 


142 


METALLURGY OF CAST IRON. 


mixed, pig about, in the same pile of ten hundred to a 
ton each, so that when charging time comes there are 
no distinct iron piles of high and low silicon to make a 
mixture of, which must be carefully guarded in order 
that no more of one than another, as desired, goes into 
the cupola; but it allows any pile to be used, and if 
the men are careless and make blunders they can do 
no harm, as with the former plan. This latter method 
involves no more labor in piling the iron on a cupola 
stage than the former and is superior in giving a 
uniform mixture, if stage room will permit of such a 
practice. 

The gradual introduction of sandless pig, cast from 
ladles, is a step which will greatly help in giving the 
founder uniform casts of pig iron, as first catching the 
metal in large ladles before pouring the pig moulds 
cannot but act as a mixer and cause the one ladle or 
cast of pigs to be more uniform in their chemical com¬ 
position than is possible by casting them in sand 
moulds, after the old method. By this plan each 
ladle’s cast of pig could be analyzed. This would give 
positive assurance of obtaining certain bodies of iron 
that would be uniform in analysis, without having to 
resort to mixing each cast of iron. These are all 
factors which strongly recommend the use of sandless 
pig iron. For methods of calculating percentages of 
silicon, sulphur, etc., as found in iron, to obtain aver¬ 
ages for making mixtures, see Chapter XXXVI. 

Another evil practice, aside from ill-mixing of sand 
cast pig iron, is the practice which some furnacemen 
making foundry iron have followed of only taking one 
analysis of one of the four to five casts a furnace may 
make during twenty-four hours, and letting the 


MIXING CASTS OF PIG IRON AT FURNACE, ETC. 143 

analysis of that one cast stand for the chemical prop¬ 
erties of the four or five casts which the furnace has 
made that day. It is not to be understood that many 
furnaces follow this practice. However, such a prac¬ 
tice should not be tolerated by any furnace claiming 
to grade iron by analysis, and is little better than 
trying to achieve desired results in re-melting by 
judging the grade of pig iron by its fracture or hard¬ 
ness. Every furnace cast should be analyzed and the 
metal of each cast kept separate when piled in the yard 
or shipped on cars, so that when the founder receives 
the iron he has not, in connection with an ill-mixed 
cast of iron, a chemical guess, but a true analysis to 
guide him aright in re-melting his pig iron. Give the 
founder a true analysis of a well sampled cast of pig 
iron, in connection with having it well mixed, or cast 
from one ladle, as in sandless pig, before the pig iron 
is charged into a cupola, and he will find that chem¬ 
istry is a guide that can be relied upon in assisting 
him to obtain the grades of iron he desires in his 
castings. 


CHAPTER XX. 


DIFFERENT KINDS OF PIG IRON USED 
AND DEFINITION OF BRAND AND 

GRADE. 

The brand of an iron refers to some characteristics 
peculiar to itself or distinct from what can be found in 
some other irons; as, for example, in the difference 
found between charcoal and coke iron, and often made 
by the use of different ores and fluxes, although the 
same fuel may be used. 

The grade of an iron refers to the different degrees 
of hardness, strength, or contraction and chill which 
may be obtained from any special brand of iron. In 
a general way high silicon or soft irons are called high 
grade irons, and low silicon or hard irons low grades. 
It has been claimed that the amount of silicon in pig 
iron, and which element chiefly regulates the grade, 
could be told by the contraction of test bars. This is 
impractical. The only sensible way to define the silicon 
or any other metalloid contents of any test bar or cast¬ 
ing is by chemical analysis. The contraction merely 
assists in defining the grade of iron and nothing more. 

Grading pig iron should mean sorting it into cars or 
piles, according to the degree of strength or hardness 
thought obtainable from it when re-melted to make 
castings. A few years back every furnace had its 
“ graders,” whose special business it was to separate 


Different kinds of rig iron, etc. 145 

the casts of iron into different piles, according to the 
grade of the pig iron by fracture. The most open pigs 
went into piles as a No. 1 iron, the smaller grained as 
Nos. 2, 3, and 4 and upward, according as the grain 
decreased in size. The greatest care was exercised in 
thus grading iron, not only because it was believed that 
the size of the grain revealed the grade, but also 
because the “ grader ” had a reputation to sustain in 
making his various piles of even grain, and the furnace- 
man was anxious to have every piece of the open 
grained iron collected by itself; for No. 1 iron brought 
him more money than a No. 2. With the advent of 
selling by chemical analysis all this was changed. 
The graders were replaced by the chemists, and the 
iron as it comes from a furnace cast is now thrown into 
one pile or car, and neither furnaceman nor progressive 
founder as a rule pays any attention to the color or the 
size of the grain of iron in the pig. The different 
brands are now generally piled, by progressive furnace- 
men, according to the percentage of silicon and sulphur 
the iron contains, as they now concede these to be the 
elements or metalloids that vary the grade of any iron 
made from like ores, fuel, and fluxes — a system 
which was advocated by the author in earlier writings, 
and the first edition of this work. 

The different brands of pig iron are classed as foun¬ 
dry, charcoal, bessemer, gray forge, basic, silvery or 
ferro-silicon, mottled, and white iron. 

Foundry iron is made with coke or anthracite fuel. 
Its silicon generally ranges from 1.00 to 4.00, sulphur 
.01 to .05, manganese from a trace to 1.50, phosphorus 
from .20 to 1.50, and is a class of iron used in the 
construction of chilled as well as unchilled castings. 


146 


METALLURGY of cast iron. 


Charcoal iron is made with charcoal fuel. Its silicon 
generally ranges from .50 to 2.00, although it is made 
with silicon as high as 5.00 per cent. The sulphur ranges 
from a trace up to .08, manganese from a trace to 1.50, 
phosphorus .15 to .75. On the whole it can be made 
richer in iron and poorer in silicon, phosphorus, and 
sulphur than a coke or anthracite iron. It is chiefly 
used for the manufacture of such castings as guns and 
chilled work, and for which it can excel all other 
brands of iron when melted in an air furnace. 

Bessemer is made with coke and anthracite fuel. 
Its silicon ranges from .75 to 2.50, sulphur .01 to .05, 
manganese .20 to 1.00, with phosphorus under .10. If 
it exceeds .10 phosphorus, it is then called “ off-Besse¬ 
mer ” and may be used as a Foundry iron. This pig 
metal is chiefly used at steel works for making steel 
and in foundries for ingot moulds, and can often be 
well used in the place of “ foundry iron ” in general 
castings not requiring good or extra fluid metal to run 
them. 

Gray forge iron is a metal of gray fracture with little 
or no grain, ranging from .50 to 2.00 silicon and from 
.03 to .20 in sulphur and which is usually high, with 
low silicon. Its manganese and phosphorus can range 
as found in general iron. This brand of iron is chiefly 
used as mill iron in puddling furnaces producing 
wrought iron, and also for the manufacture of water 
pipes, etc., often being mixed with higher silicon irons. 

Basic iron is of a similar character as gray forge, 
only its sulphur should not exceed .05, and is generally 
desired to be low in phosphorus, although it may range 
from .20 to 2.50. Its silicon is generally desired under 
1.00, and manganese may range from .30 to 1.00 or 


DIFFERENT KINDS OF PIG IRON, ETC. 147 

higher. This brand of iron is cast in chill molds or 
magnesia sand and is used chiefly in the basic open- 
hearth furnace to make steel. 

Silvery or ferro=silicon iron is sometimes made with 
all coke, and then again with coal and coke. The 
silicon ranges from 6.00 to 16.00. It is derived from 
high silicious ores and excessive fuel to give high 
temperatures in the furnace. 

Mottled and white iron is made with both coke, 
anthracite, and charcoal fuels. Its silicon ranges from 
.10 to 1.00, sulphur from .05 to .30, manganese .10 to 
1.50 or over, phosphorus .03 to .50 and upward, and 
usually high in carbon. These irons are generally the 
off product of a furnace that has not been working 
well, and are used for hard or chilled castings, or at 
rolling mills to be mixed with gray forge irons. 


1 

1 


CHAPTER XXI. 


GRADING PIG IRON BY ANALYSES. 

Previous to 1890 almost all pig iron was graded by 
fracture and piled according to the open character of 
the grain, the most open iron being used for the softest 
castings and the close grained for the hard ones, as 
shown in the last chapter. Furnacemen and founders 
gradually came to learn, by means of following chem¬ 
ical analysis, that such was not reliable and could often 
be deceptive. This has been so thoroughly demon¬ 
strated that it is now (1901) rare to find a furnaceman 
paying any attention to the appearances of fracture, 
unless a customer asks him to, and instead being 
wholly guided by a knowledge of the chemical constit¬ 
uents of the iron. While this is now the current prac¬ 
tice of most all furnacemen and about 75 per cent, of 
foundrymen, we have the evil of disabusing the general 
sense of numbering the grades which certain analyses 
will give. For example, a No. 1 iron is generally 
supposed to be such as will give soft castings in those 
ranging from one inch in thickness down to stove plate. 
Nevertheless, we have today (1901) furnacemen desig¬ 
nating pig iron as No. 1 that would run white in stove 
plate and require castings to be a foot thick or more in 
order to be sufficiently soft to be drilled, etc. An iron 
to be No. 1 by analysis should contain at least from 


GRADING PIG IRON BY ANALYSES. 


149 


2.75 to 3«ocf per cent, of silicon and sulphur from .01 to 
.04, with manganese below 1.00 and phosphorus ranging 
from .30 to 1.00. Evidence of evils to come from the 
above practice of irregularity in grading pig iron by 
analysis can be found in Mr. Seymour R. Church’s 
first edition of “ Analysis of Pig Iron.” In this work 
we find pig irons called No. 1 by their makers 
ranging in silicon from one-half of one per cent. (.50) 
to four per cent. (4.00). Furthermore, the wildest 
kind of confusion exists as to numbers and trade¬ 
marks, etc., supposed to designate the special qualities 
of the different grades of pig iron reported. 

To correct this evil and to establish uniform methods 
for grading, the author presented a paper on the sub¬ 
ject to the Pittsburg Foundrymen’s Association, 
March, 1901. This paper embodied the table seen on 
page 152 and some of the arguments presented in this 
chapter. The Pittsburg Foundrymen’s Association 
was so impressed with the importance of this work 
that a committee was appointed, with the author as 
chairman, to advance the work and carry it to the 
American Foundrymen's Association Convention at 
Buffalo, N. Y., June, 1901. To this end, circulars 
were issued regarding the work and replies requested 
as to opinion of the methods presented or suggestions 
for others. Fully two-thirds of the many replies 
received endorsed the author’s method, shown in this 
chapter, and which differs only (Table 22) in permitting 
higher sulphurs in grades Nos. 1 to 3, whereas the 
original plan restricted it not to exceed .02 for No. 1 
and .03 for Nos. 2 and 3. However, it should be born 
in mind that if sulphur reaches .04 the silicon might 
often be required at the highest point of any one 


150 METALLURGY OF CAST IRON. 

grade, as, for example, an iron with 2.75 ^er cent, of 
silicon and but .01 of sulphur would give nearly as 
soft a casting as one that might contain 3.00 silicon 
with .04 sulphur, and which is a system upon which 
all the various grades seen in Table 22, page 152, are 
divided. 

Great interest was manifested in the subject of this 
chapter at the American Foundrymen’s Association 
Convention in 1901 and several plans, aside from the 
author's, were presented. A committee was appointed, 
with the author as chairman, to continue the work and 
report progress at the convention to be held in 1902. 
It is with a view of assisting this work as much as 
possible that the author presents this chapter, and he 
would like to publish all the methods presented at 
the convention did space permit. However, any one 
desiring to read what others presented to the con¬ 
vention on the subject can do so by procuring 
copies of the American Foundrymen’s Association 
Journal for July, or the Iron Trade Review of June 

J 3> 1 9 ° 1 ' 

The author’s extended experience, obtained by closely 
following variations in the hardness of castings or test 
bars due to changes in silicon and sulphur, with the 
other elements fairly constant, is such that he can safely 
say that where sulphur is kept constant every increase 
of .25 per cent, silicon should change the grade of pig 
iron one number in all iron ranging to 3.00 or 4.00 per 
cent, in silicon. It takes less sulphur than any other 
element to effect a change in the grade or hardness of 
a casting. A change of one point of sulphur (.01) can 
often neutralize the effect of eight to fifteen points 
of silicon. This will be better understood by referring 


GRADING PIG IRON BY ANALYSES. 151 

to Table 21 which shows, approximately, the increase 
in silicon and sulphur necessary to maintain a uniform 
hardness (or a fairly constant condition of the carbons) 
in re-melted pig iron that will not vary thirty points in 
manganese and fifteen points in phosphorus, a range 
that is within the limits of what generally exists in 
irons made from similar ores, fuels, and fluxes. In 
brief, Table 21 shows that if an iron containing 2.00 
per cent, silicon should have its sulphur increased from 
.01 to .06, then in order to maintain an approximately 
equal hardness in similar test bars or castings the sili¬ 
con would have to be increased fifty (.50) points. In 
coke irons, as a rule, the lower the silicon the higher 


TABLE 21. 


Sulphur. 

.or 

.02 

•03 

.04 

•05 

2.40 

.06 

Silicon. . 

2.00 

2.10 

2.20 

2.30 

2.50 






the sulphur will be found. In establishing standards 
the amount of sulphur, therefore, should be considered 
as well as the silicon. Recognizing this fact in con¬ 
nection with the statement above, which makes a 
distinction in grade at every .25 per cent, of silicon, 
Table 22 is presented by the author as a method for 
numbering grades, which, if adopted, would greatly 
lessen the confusion and trouble we find the practice 
created previous to 1901. 

By the method seen in Table 22, page 152, one can 
form some fair idea of the hardness to be expected in 
castings from pig iron, when ordering by number in 
different grades of iron. Then again, if adopted, it 
would give a fair knowledge of the value of an iron 
from a reading of the market reports of pricCvS, by 













l S 2 


METALLURGY OF CAST IRON. 


numbers, for as a rule the more silicon in iron the 
greater its value in any special brand. Even if the 
trade should not, in time to come, require a number¬ 
ing of grades on account of the practicability of order¬ 
ing by specified analysis in purchasing foundry, 
bessemer, gray forge, mill, or basic pig irons, it will 
be essential to have some means of'brevity as by num¬ 
bers in denoting grades in the market reports of 
prices: And the method presented by the author in 

Table 22 seems to him as simple and practical, as 
could be offered or enforced by practice for such 
ends. 

TABLE 22 . 


Silicon. 

Sulphur. . 

No. 1 Iron. 
2.75 to 3.00 
.oi to .04 

No. 2. 

2.50 to 2.75 
.01 to .04 

No. 3. 

2.25 to 2.50 
.01 to .04 

No. 4. 

2.00 to 2.25 
.01 to .04 

Silicon.. 

Sulphur. 

No. 5. 

1.75 tO 2.00 
.02 tO .05 

No. 6. 

1.50 to 1.75 
.02 to .05 

No. 7. 

1.25 to 1.50 
.03 to .06 

No. 8. 

1.00 to 1.25 
.03 to .06 


Silicon.. 

Sulphur.. 

No. 9. 

.75 to 1.00 
.04 to .07 

No. 10. 

.50 to .75 
.04 to .10 




Numbering the grades from 1 to io, advancing in 
silicon .25 and sulphur .01 to .04 or more in each grade, 
as shown in Table 22, gives a range that may be said 
to include all the necessary irons that are now used in 
making castings, or for the manufacture of steel or 
wrought iron, except the so-called softeners or ferro- 
silicon irons. When purchasing ferro-silicons or soft¬ 
eners one should also know, aside from the silicon, the 
amount of sulphur, phosphorus, manganese, and total 
carbon they contain, as these elements can vary greatly 
in the same brand, or similar percentages of high 
silicon iron, vary much more than in irons having less 

























GRADING PIG IRON BY ANALYSES. 


*53 


than the 3.00 per cent, of silicon shown in Table 22. 

It is n<>t to be understood by the above that no atten¬ 
tion is to be paid to the manganese, phosphorus, or 
total carbon when ordering iron by numbers, as in 
Table 22. In some cases such will be very necessary, 
as one founder may require very high or low manga¬ 
nese, phosphorus, or total carbon, while another may 
stand a wide variation in these elements as long as the 
silicon and sulphur are best suited for the work. To 
designate the manganese, phosphorus, or total carbon 
in any system of grading by analysis in numbers, that 
is intended for universal use, could meet with little 
favor for the reason that furnacemen cannot vary 
these in unison with variations of silicon and sulphur 
in obtaining different grades. 

The manganese, phosphorus, and total carbon, the 
author believes, will be found to be best omitted from 
any universal system of numbering grades. When a 
founder desires any special percentages in one or all of 
these three elements in purchasing foundry, bessemer, 
gray forge, mill, or basic irons, he can designate just 
what he would like, aside from stating the number of 
the grade desired, and if he cannot get what he desires 
at one furnace he will have to try others. The man¬ 
ganese phosphorus, and total carbon will not, as a rule 
(as shown in Chapter XVII.), vary to any injurious 
extent for the general run of ordinary castings, in any 
one brand of iron made from like ores, fuels, and 
fluxes, in irons having less than 4.00 of silicon, as the 
silicon and sulphur can; and hence the reason why the 
author suggests confining grading by analysis in num¬ 
bers to the silicon and sulphur, as seen in Table 22. 
The class of castings in which it is generally most 


*54 


METALLURGY OF CAST IRON. 


desirable to know the manganese, phosphorus, and 
total carbon contents are such as stove plate, light 
work, and the general run of chilled castings. From 
the above it can be seen that it would generally be 
advisable for furnacemen in advertising their irons to 
state, together with the numbers of the grades or 
brands they make, what percentage or range of man¬ 
ganese, phosphorus, and total carbon their irons gener¬ 
ally contain, as there are conditions demanding varying 
percentages of these elements met with that would the 
greater enhance the sale of the irons were these points 
made known. As, for example, a founder making 
very thin castings would require higher phosphorus, 
which gives more fluidity to iron than is available in. 
some regular No. i grades. Then again, it is often 
necessary to know what manganese an iron contains, 
as when it is more than .50 its influence is to harden. 
With regard to the carbon, the “ total ” is all that is 
generally required. Giving the percentage of what is 
combined or free carbon in pig iron generally tells 
nothing further than the melting qualities of the 
metal. In this, the more the carbon is combined the 
easier or quicker the iron melts — a fact discovered by 
the writer several years ago, and confirmed by Dr. R. 
Moldenke by further experiment. If a knowledge of 
the combined or graphitic carbon contents of pig iron 
was of any real value in grading pig iron by analysis, 
grading could be done effectually by fracture or hard¬ 
ness, and the only determination required would be 
that of the total carbon, phosphorus, or manganese, 
according as information might be desired of one or 
all of these ingredients. It is not the author’s idea, that 
because the grades are divided at every quarter of one 


GRADING PIG IRON BY ANALYSES. 155 

per cent, in silicon and the sulphur ranging from .01 
to .10 per cent., as shown by Table 22, that any 
furnaceman should be compelled to fill orders from 
any one particular grade or number of iron. It is 
intended that the number ordered should indicate the 
grade of iron the consumer desired, and to fill the order 
the furnaceman could ship any number of grades from 
which an average might be obtained which corresponds 
to the grade order. If, for example, in following the 
method of grading advanced in Table 22 one should 
desire a No. 4 iron, he can accept irons ranging from 
No. 1 to No. 8 to make an average which would give 
the grade No. 4 desired, provided he knew the grade 
of every car delivered at his yard. There is surely 
sufficient margin in this method to permit the furnace¬ 
man to fill an order for any particular grade of iron 
for the great majority of purchasers. 

When foundrymen, as a rule, desire to produce cast= 
ings that are to be of some particular softness or hard¬ 
ness, and we know that a change of twenty-five points 
in silicon and two points in sulphur can cause them to 
vary from the best grade which should exist in their 
castings, the author fails to perceive the impracticabil¬ 
ity of any furnaceman accepting orders for foundry, 
bessemer, gray forge, mill, or basic pig irons by the 
method of numbering the grades from 1 to 10, which 
he has advanced in Table 22. In fact, any greater 
margin would fail to denote the true character of the 
iron desired and could cause such misunderstanding 
as to result seriously for both furnaceman and founder. 
What is required is a method of numbering that will 
denote when the character of iron is noticeably 
changed, and not something that is so flexible that any 


i5 6 


METALLURGY OF CAST IRON. 


change from one number to another would make a 
mixture which would vary so greatly as to make cast¬ 
ings so unfit for their use that they would be con¬ 
demned ; and this some of the methods that have been 
advanced would do. 

One objection made to the author’s method of grad¬ 
ing, seen in Table 22, is that errors in analysis could 
make a difference of .25 per cent, silicon and .01 in 
sulphur. Granting this to be true, as has often been 
the case, does this offer any just cause for the con¬ 
sumer not defining as closely as he may the grade he 
desires to correspond with any range in numbers from 
one to ten in Table 22? If such difference in analysis 
continued to exist they could injure the consumer as 
much as if grades were divided by one per cent, of 
silicon, instead of .25 per cent, as shown. To the 
author’s view, this is a factor that should have no 
weight in deciding the division of grades. However, 
by the use of the American Foundrymen’s Association 
standardized drillings, and the adoption of more 
uniform methods of making analyses — which is sure 
to come and for which work the author is chairman of 
a committee appointed by the American Foundrymen’s 
Association in 1901 to advance such improvement — 
there will be little excuse for any great difference in 
the chemical analysis of one sample of drillings by 
different chemists. There is much more that miofht 
be said on the subject of this chapter, but the author 
trusts that the principles herein advanced will aid the 
work of bringing about the reform in grading or buy- 
ing pig iron by analysis which this chapter advocates, 
and which almost all now concede should be accom¬ 
plished. 


CHAPTER XXII. 


BESSEMER vs. FOUNDRY IRON. 

That “ Bessemer iron ” can often take the place of 
“Foundry,” and in some cases prove a better product 
to make castings with, is a fact which few founders have 
up to this writing discovered. In the years 1893 and 1894 
of business depression, Bessemer pig was selling cheap¬ 
er than Foundry pig. A few founders, who did not re¬ 
quire high phosphorus and knew it, took advantage of 
the low price of Bessemer. Founders never having 
had an experience with Bessemer pig metal will be 
somewhat surprised to learn that the best experts can¬ 
not tell “Bessemer” from “Foundry” by judging 
of its fracture; nevertheless this is true. It is only by 
analysis that the difference is to be made known, and 
that mainly exists in the phosphorus being lower in 
Bessemer than Foundry, as illustrated in Table 30, 
page 215. 

Regular Bessemer ranging from 1.40 to 1.60 in sili¬ 
con, .010 to .030 in sulphur and about .45 in manganese, 
can often be well used for hydraulic or steam cylin¬ 
ders, heavy dies, machinery castings, and for gear 
wheels of one and one-half inch pitch and upwards. 

For ordinary machinery castings that average from 
one and one-half inches up to two inches thickness of 
metal, Bessemer ranging from 1.60 to 1.90 in silicon 
would be found to work very well. The author has 


158 METALLURGY OF CAST IRON. 

used Bessemer 1.85 to 2.00 in silicon with excellent 
success in making electric street car motor gear 
wheels. These wheels, as many know, are cast in a 
“ blank ” and the teeth are milled out. When first 
starting in to make these castings it was a “ trick ” of 
ours to take a pin hammer and strike upon the teeth 
of a spoiled wheel until the tooth would flatten out as 
if one were pounding a piece of wrought iron. This 
was partly due to low phosphorus, causing the iron 
to possess a malleable toughness. Bessemer con¬ 
taining from 1.95 to 2.25 silicon would make an excel¬ 
lent iron for all castings such as ordinary weight of 
lathes and planers. For heavy punches and shears it 
would be well to have the iron range from 1.10 to 1.30 
in silicon, with sulphur about .030 in the pig. It is to 
be remembered that owing to Bessemer being low in 
phosphorus it is not as fluid and does not run a 
mould as well as Foundry iron. Nevertheless, it can be 
melted “hot” enough to run castings as thin as 
“ stove plate,” if the liquid metal is not retained too 
long in the ladle or has not to run up too far in a mould, 
or a long distance from the “gate;” but cannot be 
recommended for such light work. 

A founder can utilize common scrap with Bessemer 
pig metal for all work above stove plate thickness, as 
in this respect sufficient silicon can be obtained in 
“ Bessemer, ” as well as in “ Foundry, ” to soften scrap, 
and thus often assist in cheapening a mixture. Sili¬ 
con does not, as a general thing, go as high in Bes¬ 
semer as in Foundry. When silicon exceeds 2.50 per 
cent, in Bessemer, it is generally called an “off Bes¬ 
semer,” the same as when it exceeds . 10 in phosphorus. 
To be over 2.50, the limit for silicon in regular Bes- 


BESSEMER VS. FOUNDRY IRON. 


*59 


semer, is not so objectionable to steel men as it is for 
the phosphorus to be over . io. Steel works will often 
accept Bessemer over 2.50 in silicon, but seldom ac¬ 
cept phosphorus over .10, unless the iron is used to 
make steel by the “ basic process,” a method by which 
phosphorus can be nearly elimininated by the use 
of a basic slag, the lining of the furnace being made 
to suit. Bessemer iron, to be such, in the regular 
sense, must not have over one-tenth of one per cent, 
of phosphorus, which is a small quantity compared 
with one per cent, often utilized in Foundry iron in 
order to give the molten metal good life and fluidity. 

It is to be understood that in all the mixtures shown 
on pages 157 and 158 the sulphur is not to exceed .030 
or the manganese .50 in the pig; if it does, then higher 
silicon will be necessary in proportion to their increase; 
also, that no scrap is intended to be mixed with the 
percentages of silicon given. Should it be desirable 
to mix scrap with the pig, which, of course, if not 
Bessemer scrap, would raise the phosphorus, to take 
the mixture out of the category of Bessemer iron, and 
in either case with any kind of scrap, it would call for 
an increase of silicon in the pig metal, so as to prevent 
the mixture from producing too hard a “grade,” as 
defined in the last paragraph, page 158. For further 
notes on Bessemer, see pages 146 and 215. 


CHAPTER XXIII. 


CHARCOAL vs. COKE AND ANTHRACITE 

IRON. 

The past advancement in utilizing chemistry in 

making mixtures of cast iron has, among other 
changes in founding, resulted in causing many firms 
to make castings of various types from coke irons, 
whereas for years past it has been thought that char¬ 
coal was the only brand permissible to be used. It is 
no reason because malleable iron founders and some car 
wheel and chill roll makers have discovered that coke 
and anthracite iron can be made to answer their pur¬ 
pose that charcoal iron is sure to pass into oblivion. 

A peculiarity between “ Bessemer ” and “ Foundry” 
iron lies in the fact that one cannot be told from the 
other in yards, single pigs or piles, in judging them 
by fracture. This cannot be held to be true of char¬ 
coal vs. coke iron. If there were two yards of pig 
metal, one being charcoal and the other being all coke 
or anthracite iron, any one at all familiar with such 
irons can generally tell the class of iron each yard con¬ 
tains. We may occasionally see single pieces or piles 
of coke or anthracite pig iron which will resemble 
charcoal so closely as to make it difficult to decide its 
true brand, but, in a general way, charcoal iron is 
distinguishable from coke or anthracite iron. 


CHARCOAL, VS. COKE AND ANTHRACITE IRON. l6l 


The greater the temperature in a blast furnace, the 
more silicon can iron absorb. The lower heat derived 
from charcoal furnaces causes less silicon to be taken 
up than by iron in coke or anthracite furnaces. From 
this circumstance, combined with the fact that charcoal 
fuel is free from sulphur, we find that charcoal iron 
generally contains very little sulphur, with low silicon. 
The more general uniform workings of charcoal over 
coke furnaces and absence of sulphur in charcoal iron, 
leaves much less chance for the other elements — 
silicon, manganese, phosphorus, etc., to cause radical 
variation in the size of the grains; and hence we find, 
as a general rule, that charcoal iron is more uniform in 
grain than coke or anthracite irons. 

The greater strength and homogeneity of charcoal 
over the present coke or anthracite iron, also in its pos¬ 
sessing very low sulphur, as a rule, will, in the author’s 
estimation, forbid its expulsion from the market. There 
are certain kinds of work for which charcoal will gen¬ 
erally prove superior over other irons. These can be 
classed in the following order: (i) Chilled work, (2) 
gun manufacture, (3) hydraulic and steam cylinder 
castings. Heavy gearings and large castings require 
high strength, combined with softness sufficient to 
permit finishing. Coke iron is now used in nearly all 
the specialties, but where it is intended to replace 
charcoal special care is often necessary to watch the 
sulphur contents in order to get them as low as possible. 
Where the coke or coal fuel and ore are very low in 
sulphur, coke or anthracite iron can be made which 
may often answer many purposes of charcoal pig. 
Charcoal pig iron, on the whole, is poorer in silicon 
and phosphorus, as well as sulphur, than a coke or 
anthracite pig metal.. 


162 


METALLURGY OF CAST IRON. 


Charcoal fuel contains no sulphur, and if the ore 
and flux are likewise free from it an iron will be 
obtained free of sulphur — something which cannot be 
said of coke or anthracite iron. Let charcoal iron be 
melted in an “ air furnace ” instead of a cupola, where 
the iron must be mixed with coke or coal, and it can 
then clearly demonstrate its superiority over coke or 
anthracite iron. To melt charcoal in a cupola greatly 
impairs its superior qualities and brings it largely on 
a level with coke or anthracite iron. Coke or anthra¬ 
cite will often answer well for an approximation, but 
to obtain the very best mixture for chilled work, guns, 
etc., charcoal iron will ever remain the king metal of 
cast irons, when melted in an air furnace, unless mod¬ 
ern advance arranges to eliminate sulphur, etc., from 
metal and “ refine ” the iron before it is cast into pigs 
in such a manner as to be relied upon, or while being 
re-melted in the cupola. For analyses of charcoal iron, 
see pages 268, 269 and 299. 

Refining iron means the lowering or removal of 
some impurities — carbon, silicon, and manganese being 
classed with them in this instance. The process, of 
course, increases the percentage of iron in the product 
but, for casting purposes, should not be carried too far. 
Unfortunately, sulphur and phosphorus will not go as 
readily as manganese and silicon, in fact, in the ordi¬ 
nary refining of a bed they will not go at all; hence 
the value of refining is to be looked for in the removal 
of the mechanically mixed slag, the lowering of the 
silicon and manganese, .and, in some cases, the carbon 
contents, with the consequent increase in the com¬ 
bined carbon of the product and the closing up of the 
grain. 


CHAPTER XXIV. 


THE DECEPTIVE APPEARANCE OF THE 
FRACTURE OF PIG IRON.* 

Progressive furnacemen and foundrymen have ex¬ 
perienced few changes in their practice that have been 
more radical in character or far-reaching in benefit, 
than those made by the adoption of chemical analysis 
to correctly define the grade of pig iron. The change 
was such a sensible one that many are annoyed that in 
this age of science they have not always utilized chem¬ 
istry in their practice. And not until we bring to 
mind the old-time prices paid for castings, can we 
realize why commercial success was at all possible to 
many following the old school methods of judging the 
grade of pig iron. While the benefits obtained by 
adopting chemical analysis in foundry practice are 
generally very great, the advance has been slow. This 
is on account of the prejudice, selfishness, and conser¬ 
vatism that all new departures in any calling must 
meet and set aside. The opposition that existed, and 
is yet in force, against the adoption of grading by 
chemical analysis has caused the author to ex¬ 
pend much time and money in its defence. It is 
often interesting to investigate the reasons for 
rejecting the new-school practice that members 

* A revised edition of a paper presented by the author to the 
Pittsburg meeting of the American Foundrymen’s Association, 
May, 1899. 



164 


METALLURGY OF CAST IRON. 


of the old set up against its advocates.* Not long 
ago, as an example, in discussing the merits of work¬ 
ing by chemical analysis with an old experienced 
founder who had never mixed his metals by this 
method, he expressed the belief that if a cast of nice 
open-grained pig iron did not give a softer iron than a 
close-grained pig mixture it was because of some local 
condition not being controlled; as, for example, he 
claimed that the cupola might not have been daubed 
properly, or the bed not well lighted before the iron 
was charged, or the charge might not have been placed 
evenly, or that the stock hung up. Then again, he 
claimed that it might be due to other conditions, such 
as are found in bad scrap iron, changeable weather, 
difference in fuels, fluxes, or variable blast pressures, 
to cause fast or slow melting, etc. When, as practical 
foundrymen, we know that such varying conditions 
may at all times affect mixtures and cause a soft iron 
to be hard, we are forced to confess that the old-school 
fellows may continue their method for years, if they 
are in any way prejudiced against the new-school prac¬ 
tice, before events may transpire to convince them that 
by following chemical analysis they will greatly 
decrease their mishaps, for the simple reason that if 
an open cast of pig metal does happen to give them a 
hard iron they have nearly a dozen evils or excuses to 
which they can charge their poor results. 

There are several ways in which self=interest can 
retard the progress of chemical analysis in founding. 
As an example we will cite two cases. The first lies 
in the power of furnacemen knowing the utility of 
chemical analysis, and lack of that knowledge by the 

*For the latest in support of old-school fallacies and retarding 
the advance of the new, see page 179. 



APPEARANCE OF THE FRACTURE OF PIG IRON. 165 

old-school foundrymen. To illustrate how the latter 
may be duped by making them think their practice 
correct: A well-known firm, standing high in its 
ability to cast heavy machinery, recently sent an order 
to a furnaceman for one car of strictly all open-grade 
iron, to make strong castings for a special job. The 
author was consulted as to the analysis necessary, as 
the furnaceman knew he could select the open iron in 
almost any grade of silicon. Upon learning the char¬ 
acter of the castings required from the furnaceman, the 
author recommended silicon between i.oo and 1.25, 
with sulphur about .030. A car of as beautiful open¬ 
grained coke iron as was ever seen was sent to the 
founder. Its results pleased him so much that in a 
few weeks the second order, “ Send me another car of 
strictly open-grade iron, same as last,” came in. The 
furnaceman, knowing the utility of chemical analysis, 
referred to his books and duplicated his last analysis, 
being careful, of course, to load nothing but an all 
open-grained iron, as, if he had sent a close-grained 
iron it would have been condemned. Now, this fur¬ 
naceman is not going out of his way to advocate the 
utility of chemical analysis to that foundryman, and it 
would be almost useless for anyone else to attempt to 
do so, as the founder is stubborn in the belief that it 
is the open-grained iron of that peculiar brand which 
was wholly responsible for obtaining the results he 
desired. Then again, should this founder, on account 
of a difference in price, change to another furnaceman 
who was not thoroughly posted in making mixtures 
for different castings, and who might not have had the 
forethought to consult some expert of the new school 
in regard to analysis, the chances are that his open- 


i66 


METALLURGY OF CAST IRON. 


grained iron would have given him too weak a result 
in his castings, on account of there being chances of 
its being too high in silicon; or again, by ignoring 
analysis and taking open iron wherever found, he 
might receive some so low in silicon as to make his 
casting white iron. The author has heard shippers 
say, “ Well, if the fool does not know better than to 
order iron by fracture, let him suffer his losses. 
The author has known cars of nice open iron to have 
but .75 up to 1.25 in silicon go to founders wishing 
soft light castings, simply because they insisted that 
the iron be opened-grained and ignored analysis. 
Such iron could do nothing other than give hard 
iron in any castings less than 2 inches thick. But as 
long as this founder had his open-grained iron he 
could turn to changes in the fuel, scrap irons, blast, 
weather, methods of charging, etc., to make excuses for 
his ill results, and not until such a paper as this, ex¬ 
posing the true cause of his trouble, might by chance 
fall into his hands is there any hope of his being made 
a follower of the new-school practice. 

The second illustration of where self=interest has 
retarded the advance of chemical analysis lies in 
advocating the use of testing machines, as affording 
the founder sufficient means to regulate his mixtures 
without resorting to chemical analysis. Testing ma¬ 
chines have their place, and most founders should 
possess one, but the practice of taking advantage of 
the prejudice, etc., of the old-school methods to antag¬ 
onize the advance and true utility of chemical analysis 
in the self-interest of a more rapid sale of testing 
machines, is to be deplored. 

The foundation of the old=school method in regulat- 


APPEARANCE OF THE FRACTURE OF PIG IRON. 167 

ing mixtures is based on the belief that the appearance 
of pig fractures, or their hardness, truly defines the 
character of iron as to the degree of hardness it will 
give in castings. The founder's own experience in 
knowing that he can make soft and hard castings from 
the same ladle, and at one pouring, if he choose to so 



construct his molds as to make a difference in the cast¬ 
ing rate of cooling, should be sufficient to prove to him 
why it is possible for two furnace casts of pig metal 
that are alike in chemical analysis, or will give the 
same results when melted, to differ so widely in 
appearance that a fracture from one furnace cast 
will seem close-grained or hard in the pig, while the 
other will be the reverse. A founder can take the same 
ladle of iron, and by pouring part of the metal 
into a sand mold and part into one that will 






i68 


METALLURGY OF CAST IRON. 


chill or solidify it quickly, produce a fracture that 
will be close-grained in the one case and open in the 
other. This is just what the fumaceman does in 
making sand cast pig iron. One part of his tap, or 
cast of iron, may run so slowly from his furnace as to 
“ chill the metal,” as it is called, before it reaches the 



pig beds, while another tap or cast may come so fast 
as to fill the pig beds so rapidly, or make the pigs 
larger, that it will take much longer for the metal 
to solidify, and thus make the pigs more open 
grained than ‘ ‘ casts ’ ’ poured slower, or pouring smaller 
pigs. Again, one tap or cast at a furnace may give 
much hotter iron than another, and it is natural that 
the dull iron should cool faster than the hot, and, if 
both run at the same speed from the furnace down the 
long runners to the pig beds, the duller metal will 




APPEARANCE OF THE FRACTURE OF PIG IRON. 169 

give the closer grained iron. All should perceive 
from this why the same kind of iron may have in one 
cast a close grain, and in another an open grain. 
As there are but few molders or founders who have 
ever had the opportunity of witnessing a furnace cast, 
this explanation of its workings, combined with their 
own foundry experience, should assist many to realize 
why the fracture or hardness of pig metal is an unre¬ 
liable guide to the iron’s true grade. 

As there are those who are still sure to contend that 
open pig fractures mean a soft iron and a close-grained 
iron a hard one, and if different results are obtained in 
castings to charge such to changes in fuel, scrap iron, 
fluxes, blast, weather, etc., the author has selected 
samples of pig iron shown in Figs. 37, 38, and 39, 
coming from two different casts, that are a fair repre¬ 
sentation of the whole cast or car of iron. If any of 
the old-school founders were asked to select from these 
a cast or car of iron to give soft castings, they would 
pick out iron such as sample A, seen in Figs. 37 and 
39, while if they desire to make strong or hard castings 
they would select such irons as are represented by 
sample B, seen in Figs. 38 and 39. In fact, if they 
were asked to use such a cast or car of iron as that 
represented by B, they would claim that on account 
of its close grain and the blow-holes seen at B, the iron 
was hardly fit for sash-weights, let alone to think it of 
any value to make soft castings. 

In order lo convince the skeptical, or those not con¬ 
versant with chemical analysis, or the effect of one 
metalloid upon another, that they are in error, the 
writer melted down about one hundred pounds of each 
of the grades A and B in his twin-shaft cupola, seen 


170 


METALLURGY OF CAST IRON. 


on page 241. In melting these irons A and B to make 
the castings seen in Figs. 37 and 38, which range from 
one-eighth to two inches in thickness, all conditions 
were alike as near as it was possible to have them, so 
that if the open-grained iron, A, gave a hard casting, 



changes in fuel, scrap, blast, weather, etc.— the old 
excuse — could not be offered as an explanation to 
befog the true cause A sample of the pig used and 
sections of the castings made from them the author 
displayed at the meeting at which this paper was read 
so that all might see them, and all were invited to take 
drillings from the specimens and report whether their 
analyses agreed with those presented in Table 23, in 
which the letter A represents the analysis obtained 




APPEARANCE OF THE FRACTURE OF PIG IRON. 171 


from the pig and the castings seen in Fig. 37, while B 
gives that secured from Fig. 38. 


TABLE 23. 


Samples. 

Silicon. 

Sulphur. 

A /]«»■,. 

1-25 

.035 


i -15 

.070 

B J pi g.- .. 

2.86 

.040 

1 Castings. 

2.67 

.060 


The fracture seen in Fig. 39 being enlarged will 
afford a better study of the difference existing between 
the grain of the pig, samples A and B. To the new- 
school founder Table 23 is sufficient to define the 
results, or whether samples A and B would give the 
soft or hard iron upon being re-melted; but for the 
old-school of founders Tables 24 and 25 will best serve 
such ends. A study of these latter tables will show 
them that the pig B which would have been condemned 
by those wishing to make soft castings, gave by far 
the least contraction and chill, so much so that the test 
pieces, only one-eighth inch thick, as seen at H, Fig. 
38, are so soft as to be readily drilled, while at K, Fig. 
37, made from sample A, a drill was broken in trying 
to get a hole through the thin piece one-eighth inch 
thick. In fact, we were foolish to try to touch it with 
a drill, as the metal was nearly all chilled or white in 
color. It is also to be said that all the other test pieces 
ranging from Nos. 2> to 12 that were made from the 
pig, sample A, were also much harder than those made 
from sample B. In measuring the depth of the chill, 
pieces were broken off one end of the test bars as 
seen at P, Fig. 37. 



















172 


METALLURGY OF CAST IRON. 


TABLE 24. 

RECORD OF TESTS TAKEN FROM IRON SEEN IN FIG. 37. 


No. of Bars. 

Size of Bars. 

Contraction. 

Chill. 

1 

Vs x iy 

•293 

Nearly white. 

2 

V x iy 2 

.266 

V deep. 

3 

Vs x iy 2 

.242 

y deep. 

4 

y x iy 

.220 

3-16 deep. 

5 

H* iy 

.200 

3-16 deep. 

6 

H x iy 

.182 

Vs deep. 

7 

Vs x 1 y 

.165 

V& deep. 

8 

1 x i y 

.150 

3-32 deep. 

9 

iy x iy 

00 

3-32 deep. 


TABLE 25. 

RECORD OF TESTS TAKEN FROM IRON SEEN IN FIG. 38. 


No. of Bars. 

Size of Bai s. 

Contraction. 

Chill. 

1 

^8x1^ 

.178 

.03 deep. 

2 

y x iy 

.163 

.02 deep. 

3 

H x iy 

.150 

.01 deep. 

4 

y x iy 

• 137 

Hardly perceptible. 

5 

H x iy 

.125 

No chill. 

6 

H x 1 y 

.112 

No chill. 

7 

Vs x 1 y 

.101 

No chill. 

8 

1 x iy 

.92 

No chill. 

9 

1 y x iy 

.88 

No chill. 


This chill was obtained by causing the end of the 
test bars farthest from the gate to be formed by a 
wrought iron bar three-fourths by two inches wide. 
The twelve test bars of each set were molded in green 
sand and poured from one gate. The same “ temper ** 
of sand was used for both flasks, and the iron was 
alike in fluidity at the time of pouring. Only nine 
tests out of each of the twelve bars seen in Figs. 37 
and 38 are given. 

To further demonstrate the deceptive appearance 01 
fractures in pig iron, analyses of three pieces of pig 























































































APPEARANCE OF THE FRACTURE OF PIG IRON. 



FIG. 40. —NO. I IRON BY FRACTURE, BUT NO. 8 BY ANALYSIS. 



FIG. 41. —NO. 7 IRON BY FRACTURE, BIT NO. 4 BY ANALYSIS. 



FIG. 42. —NO. 9 IRON BY FRACTURE, BUT NO. I BY ANALYSIS. 


















i74 


METALLURGY OF CAST IRON. 


samples are given in Table 26 and illustrated in Figs. 
40, 41, and 42. 

TABLE 26 , — CHEMICAL ANALYSES OF PIG SPECIMENS. 


Fig. 

Silicon. 

Sulphur. 

Manganese. 

Phosphorus. 

40 

.98 

.015 

•30 

.092 

4 i 

1.82 

.018 

-35 

.096 

42 

3-30 

.017 

•34 

.080 


The author has numbered the above irons from the 
appearance of their fracture and not from the chemical 
analysis, as an iron 3.30 (Fig. 42) in silicon with sul¬ 
phur as shown would prove a good No. 1 iron when 
re-melted, but the fracture would assert it to make No. 
9 or hard iron. Then again, in judging by fracture Fig. 

41 would make a very hard iron, while Fig. 40 would make 
a very soft casting, when in truth the reverse results 
would be obtained by both as shown by the analyses. 
It will be seen by the Table 26 that the chemical 
analyses of these three samples are practically all the 
same excepting in the silicon contents. The author 
could present any number of specimens which would 
be as deceptive to the eye in judging their grade by 
fractures, etc., but what is given in this chapter should 
be sufficient to illustrate that we cannot be always 
correctly guided by the appearance of the fracture (or 
hardness of pig iron, as treated in the next chapter) to 
define the grade of iron when re-melted or poured in 
castings. The pig samples seen in Figs. 40, 41 and 

42 are numbered after the method advanced in table 
22, page 152. 














CHAPTER XXV. 


THE IMPRACTICABILITY OF HARDNESS 
TESTS FOR GRADING PIG IRON. 

A drill test was advocated, at the close of 1900, as 

being practical to define the grade of pig iron or the 
degree of hardness it would impart to castings. There 
are fonndrymen today who could be misled into believ¬ 
ing such a system practical, and would buy the machine 
advocated for this work. A hardness test for pig iron 
is no more or less than judging iron by the appearance 
of its fracture, a method which has been in vogue for 
a century but now known to be wholly erroneous. 
There are two ways of producing different degrees of 
hardness in pig iron or castings, one is by varying the 
percentages of silicon, sulphur, manganese, and phos¬ 
phorus in iron, the other by varying the rate of solidi¬ 
fication and cooling to a cold state, also shown on pages 
167 and 168. Alterations in either of these factors can 
cause the carbon to take the combined or graphitic 
form. The higher the combined carbon the harder 
the iron, and the more the graphitic carbon is in 
evidence the softer the iron. 

An illustration of what may often be expected in the 
differences of hardness between two casts of pig iron 
that would give like grades or softness in like castings, 
is seen in Nos. 1 and 2, Fig. 43. Were these samples 


176 


METALLURGY OF CAST IRON. 


tested for hardness they would be found so different 
that anyone, guided by hardness tests, would say that 
No. 1 would make a very soft casting while No. 2 
would make a very hard one, when in fact each will 
give like softness in like castings and treatment in 
cooling. These samples were drilled with a press run¬ 
ning at uniform speed and pressure. It took eight 
minutes to drill No. 1 and twenty-two minutes to drill 
No. 2, a difference of fourteen minutes. A half-inch 
twist drill was used and the method of drilling will be 
seen by the half holes on the back of the specimen seen 
in No. 3. The difference in the hardness of these 
samples, it is to be remembered, is found in samples 
of like analysis, excepting in combined carbon and in 
iron, coming from the same tap and cast in sand 
moulds. As long as uniformity in making iron cannot 
be achieved, as is illustrated in Chapter XXIV., we 
may expect that the state of the carbon or hardness of 
pig iron will vary, and often not be in accordance with 
the grade results as shown by the percentages of 
silicon, sulphur, manganese, and phosphorus which 
will be in the pig iron. It will appear ridiculous to 
those who know, by experience and research, the 
deceptive nature of the appearance and hardness of 
sand-cast pigs that any one should now, at this day of 
advancement in the metallurgy of cast iron, try to 
introduce a hardness test to define the grade of pig 
iron as now being generally cast. 

It is not to be understood that every cast of pig 
metal is deceptive to the eye, or hardness test. It may 
be that three-fourths of all the iron cast at some 
furnaces may possess a true fracture of hardness or 
accord with the amount of silicon, sulphur, etc., an 


IMPRACTICABILITY OF HARDNESS TESTS FOR PIG IRON 


*77 



FIG. 43.—SAMPLES OF PIG IRON DIFFERING IN HARDNESS UNDER TEST 
BUT MAKING CASTINGS OF LIKE SOFTNESS. 








178 


METALLURGY OF CAST IRON. 


iron contains. Then again, it may be that nine-tenths 
of all casts would possess true fractures of hardness. 
Even if this latter were so, are we not justified in con¬ 
demning the practice of being guided by the appearance 
of fractures or hardness, especially when there exists 
another method (chemical analysis) which is known to be 
positively correct in defining the grade of any brand of 
iron every time it is employed? At the best, what sense 
is there of any foundryman taking chances of having 
one out of ten heats result in wrong grades of iron in 
his castings when, by following chemical analyses, he 
can have not only all his heats acceptable but also have 
them far nearer the grade he desires than is ever pos¬ 
sible by being guided by fractures or hardness? 

From careful observation In contrasting appearances 
of fractures with chemical analysis, with heats melting 
from 70 to 100 tons, the author can say that fully one- 
half of the furnace casts of pig which he used would 
have given him grades of iron different than what he 
desired in his castings, and some of the heats would 
have been practically worthless and caused a loss of 
much money and trade, had he been guided by the 
old-school method of judging by fracture or hardness. 
From the author’s observation and experience, he 
believes it safe to say that from a third to half of the 
iron made will not, at the present day, agree in the 
appearance of fracture or hardness with the analysis. 
The margin that some founders possess in having their 
castings accepted when the grade of iron is not what 
it should be, causes them to often be indifferent in 
exacting the best obtainable. However, the day is 
coming when such practice will not be tolerated and 
all founders will, as a rule, be forced by competition to 


IMPRACTICABILITY OF HARDNESS TESTS FOR PIG IRON. I 79 

obtain that which is best to exist in their casting's as 
nearly as possible. When this day arrives we will 
hear no more of being guided by the appearance of 
fractures or hardness, unless, by better regulation of 
furnace workings and the casting of metal from ladles 
into iron chill moulds may, in years to come, cause the 
appearance and hardness of fractures to agree with the 
chemical analysis; but this is doubtful of achievement 
to the perfection that should be obtained. 

In the “ Foundry ” of November, 1901, a statement is made, 

under the head of “ Cast Iron Notes,” inferring that two furnace 
casts of gray pig iron of the same analyses and brand, but of 
different grain or fracture/ would give a different grade or charac¬ 
ter of iron in like castings. This is practically the same as 
thinking to correctly judge pig iron by its hardness, as, in either 
case, the hard or close grained pig has more combined carbon 
than the soft or open grained pig and as a fact, the samples Nos. 
1 and 2, Fig. 43, are of like analyses, excepting the graphitic and 
combined carbon, but, if remelted under like conditions, as could 
be done in the cupola shown on page 241, castings of like softness 
would be produced; at least, so close that there would require to 
be a much more radical difference in the grain of two furnace 
casts, of like analyses in the same brand, than is shown by the 
samples Nos. 1 and 2, Fig. 43. The difference that a very open 
and very close grained iron of the same analyses and brand could 
make would be in the most close grained iron giving a slightly 
softer casting than the open iron, after the principles presented 
in Chapter 47, pages 337 to 339. However, there is no reason 
why any one should make it a point to insist on accepting only 
open or close grained iron in connection with exacting any certain 
specified analyses from blast furnaces, as the slight difference 
possible in the most radical cases of open and close grained iron 
can be regulated by a slight variation in silicon when making a 
mixture, and which anyone can easily do, if they so desire. 


CHAPTER XXVI. 


ORIGIN AND UTILITY OF STANDARD¬ 
IZED DRILLINGS. 

To test the practicability of obtaining uniform anal¬ 
yses of one quarter piece of pig iron, samples 
of well mixed pig drillings were sent out by 
the author, during the summer of 1897, to twenty 
leading chemists in different parts of the country to be 
analyzed, with a view of ascertaining how closely their 
results would agree. The reports were such as were 
anticipated. No two were alike, and the difference 
between the 'extremes was so great that a founder 
being guided by one extreme, in forming a comparative 
measure for making mixtures, could, should he accept 
the other, sustain great losses, or obtain a grade of 
metal far different than what should exist in his cast¬ 
ings. The evil results obtained from such variations 
of analysis were such as to prevent chemistry ever 
being universally established in founding. Exhibiting 
the weakness of chemical methods, as did the author 
by the publication of the reports obtained, caused 
another party to send out samples of drillings to fifty 
chemists with the view of getting better results. 
No. 1 of Table 27 shows the difference in the great¬ 
est variations of the analyses reported to the author, 
and No. 2 shows the greatest variation in the analy¬ 
ses obtained by the second party: 


ORIGIN AND UTILITY OP STANDARDIZED DRILLINGS. l8l 


TABLE 27. 



Sil. 

Sul. 

Phos. 

Mang. 

C. C. 

G. C. 

T. C. 

Variation i. 

•19 

.028 

.029 

.19 

•34 

.82 

.48 

Variation 2. 

.21 

.015 

.031 

•23 

•59 

•77 

1.09 


Those making a study of the reasons for such differ¬ 
ences in results as shown by Table 27, will find that it 
is due to the fact that chemists are unable to know 
positively the correctness of their results without 
checking them by some known standard. Almost 
every trade possesses some standard by which its arti¬ 
sans can tell whether their labors have been productive 
of the perfection desired. The appearance of the 
finished casting indicates to the furnaceman or founder 
the result obtained from his iron. A trial of a machine 
or an engine demonstrates to the machinist or engineer 
the perfection he has attained, but the completion of 
an analysis by a chemist presents no tangible evidence 
of the accuracy of his results. The only way a chem¬ 
ist can know the correctness of his results, or give 
others any assurance that his work is correct, is by 
having them checked by others, or by analyzing stand¬ 
ardized drillings that have been determined by com¬ 
petent chemists to find whether results agree. The 
latter method of checking is similar to the use of 
standard weights to test the accuracy of scales. No 
laboratory is complete without its standardized drill¬ 
ings, any more than would be a furnace or foundry 
without standard weights for occasional testing of 
scales. This necessity has led many chemists here¬ 
tofore to make their own standards. An observing 
person having the opportunity to visit chemical labor- 






















182 


METALLURGY OF CAST IRON. 


atories would often find the chemist using these 
standards, to test chemicals, short-cut methods, or 
the correctness of results that had been questioned. 
The process by which individual chemists obtained 
their own standards was, as a rule, long and tedious. 
It often took from four to six months to get in all the 
results. Then again, as a rule the results varied so 
much that the average accepted for a standard seemed 
more like guesswork than the result of accurate work 
and methods. The variation in analyses thus obtained 
has often caused great difference in standards in use 
in different circles and perplexed managers of steel 
works, furnaces, founders, and chemists rather than 
helped them to correct evils and prevent losses. It 
was the opportunity of observing the practice of blast 
furnace chemists making their own standards that 
caused the author to conceive the idea of one central 
agency, from which all could obtain standardized drill¬ 
ings, which had been determined by a few of our best 
known chemists. 

After devising a plan for a central agency or bureau 
for the distribution of standardized drillings, the author 
presented a paper to the Pittsburg Foundrymen’s 
Association, April 25, 1898, setting forth the need of 
greater uniformity in analysis and suggesting, in 
outline, his plan for establishing a central agency. 
At this meeting a committee was appointed with the 
author as chairman to introduce the project before the 
American Foundrymen’s Association at Cincinnati, 
June, 1898. This convention unanimously approved 
the project, and appointed a committee to proceed with 
the work. This committee consisted of Dr. Richard 
Moldenke, now secretary of the A. F. A., New 


ORIGIN AND UTILITY OF STANDARDIZED DRILLINGS. 183 

York; James Scott, superintendent of the Lucy 
Furnace, Pittsburg; P. W. Gates, president of the 
Gates Iron Works, Chicago, and E. H. Putnam, super¬ 
intendent of the Moline Plow Works, Moline, Ill., with 
the author as chairman. The appointment of the 
committee gave a sound basis on which to work, but 
the importance of the reform and the obstacles which 
had to be overcome before the same could be estab¬ 
lished were realized by but few. The first work of 
the committee was to adopt the plans advanced by the 
author in his paper before the Pittsburg Foundry- 
men’s Association, April, 1898, and which secured for 
us the services of Prof. C. H. Benjamin to supervise 
the work of making the drillings, and of Prof. A. W. 
Smith to carry forward the work of preparing, stand¬ 
ardizing, and packing the samples; also, the services 
of Booth, Garrett & Blair, Andrew S. McCreath, 
Cremer & Bicknell to analyze the drillings, the average 
of the four results being accepted as a standard. 

One of the greatest obstacles in the way of estab¬ 
lishing and maintaining a central standardizing agency 
lay in the difficulty of obtaining a sufficient amount of 
uniform turnings or drillings from one sample of iron, 
free of sand, grit, slag, etc., to permit all laboratories 
to obtain a pound or more of them. As a rule, chem¬ 
ists have found it difficult to obtain twenty-five pounds 
of clean, uniform, and reliable samples. A study of 
this phase of the subject will show that the practica¬ 
bility of establishing and maintaining a central stand¬ 
ardizing bureau is largely dependent upon the ability 
of the founder to make large castings weighing five 
hundred pounds or more, from which could be obtained 
a large amount of clean, uniform drillings. For this 


184 


METALLURGY OF CAST IRON. 


reason, a well-known writer has aptly said that the 
establishing and maintaining of a central standardizing 
agency is properly foundrymen’s work. As the mak¬ 
ing of these castings involves principles of founding 
interesting to many, we illustrate the plan used, which 
is as follows: A mold of dry sand, for the outer body 
and a dried core for the inner, are made as seen in the 
plan and section view of Figs. 44 and 46. The con¬ 
struction of the mold explains itself. The secret of 
getting a clean, solid casting lies mainly in the method 
of gating and pouring it. At A is a gate leading down 
to the bottom of the mold at an inlet at D. The 
round gates B, seen at the top of the mold, are placed 
about four inches apart and are one-half inch in diam¬ 
eter. A riser is seen at E. In starting to pour the 
mould, the molten metal is directed to drop from the 
ladle into the basin at the point marked W, in a way 
that will allow it to flow gently down the gate A and 
enter the mould at D to prevent the bottom being cut 
by the top gates. When from thirty to fifty pounds 
of metal has entered the mould, a quick turn of the 
ladle empties a large body of the metal into the pour¬ 
ing basin, quickly filling all the gates at B; this then 
drops the metal down upon that which is rising from 
the stream flowing in at D. This action is kept up 
until the mould is filled and the metal runs out at the 
riser E. After this point is attained, the pouring is 
slackened and a steady stream maintained until from 
three hundred to five hundred pounds of metal has 
flown through the riser E to run down the incline seen 
at S into the scrap hole X. The effect of allowing 
such a large body of metal to flow through the mould 
by making it enter the gate at A is to keep up an agita- 


ORIGIN AND UTILITY OF STANDARDIZED DRILLINGS. 185 

tion after the mould has been filled, which in turn is 
most beneficial in causing the metal in the mould to 
mix well and counteract variations in structure that 
might otherwise take place. The metal dropping 



from the top gates B causes a disintegrating action, 
cutting into fine particles any dirt that might accumu¬ 
late upon the surface of the rising metal, and which, were 
it not thus chopped up, as it were, into fine particles, 
would gather in large lumps and be caught and held 
fast in the mold walls, with the result that dirt spots, 








































i86 


METALLURGY OF CAST IRON. 


etc., would be found in the casting- when the skin was 
removed by a drill, lathe, or planer. Again, the fact 
that the metal drops from the top of the mold besides 
entering at the bottom, causes the top body of the 
rising metal to be as fluid as that at the bottom, which 
is also beneficial in causing all scum and dirt to float 
upward with the metal to the top of the mold or 
“ riser head.” Where metal fills a mold all from the 
bottom it becomes rapidly duller in rising to fill the 
mould and can leave dirt scattered throughout the 
casting, an evil which will be readily seen. Fig. 45 
shows a section of the casting obtained from the 
mould, with the exception of four lugs cast on to assist 
in holding the cylinder or casting in the lathe while it 
is being turned. It will be well to state that there is 
no difficulty in obtaining castings weighing tons which 
might serve for standardizing purposes, if cast upon 
the principles herein described. Before starting to 
make these castings, investigations were made as to 
the variations in metalloids most likely to be demanded 
by the trade in general. It was found that samples 
high, medium, and low in silicon, sulphur, manganese, 
and phosphorus would satisfy most of our country’s 
laboratories as far as iron standards were concerned. 
To obtain this variety of standards called for the mak¬ 
ing of three distinct castings of different grades of iron. 
These were cast with iron melted in a small cupola, 
under the direction of the author, at the Thos. D. West 
Foundry Co., after the plan herein described. 

To obtain the turnings or drillings, which had to be 
fine enough to pass a 20-mesh sieve, was no easy mat¬ 
ter and rather a costly affair. To get one pound of 
drillings per hour was thought to be good work. The 


ORIGIN AND UTILITY OF STANDARDIZED DRILLINGS. 187 

plan of securing these turnings or drillings was first to 
take off about one-eighth of an inch from the surface 
of the casting. These first turnings were cast aside, 
as they contained more or less scale or refuse formed 
on the surface of the casting by the fusing action of 
the molten metal upon the sand forming the face of 
the mould. After this surface had been turned off 
and all debris removed carefully from the lathe, the 
cylinder was turned until about a one-quarter inch 
thickness of the inner shell remained. The turnings 
obtained from the body after the one-eighth inch 
thickness was removed from the surface were the ones 
taken for standardizing purposes. It should be stated 
that about a one-half inch thickness at the botom and the 
“ riser head ’ ’ of two inches at the top were not disturbed, 
so as not to have the scale on the bottom of the casting, 
or any dirt that would be collected at the top end 
mixed with the turnings obtained from the inner body 
of the casting. After the turnings had been thus 
obtained they were passed through a 20- and 40-mesh 
sieve. This done, the drillings were then spread out 
on a large carbonized cloth and thoroughly mixed. 
The mixing having been perfected, bottles holding 
one-third of a pound were placed in convenient posi¬ 
tion and filled with the drillings, by having a scoop 
holding sufficient drillings to give each bottle an equal 
portion from every filling of the scoop. In filling the 
scoop, drillings are taken from different parts of the 
spread so that all bottles will contain some of every 
portion of the drillings. Repeated analyses of differ¬ 
ent bottles or samples have proved the mixing to be 
all that could be desired. 

The samples made up to 1902 are designated as A, B, 


i88 


METALLURGY OF CAST IRON. 


C, and D. Sample A, which has been ground to pass 
a 40-mesh sieve, gives one total, combined carbon and 
one graphite. Sample B gives a low silicon, a medium 
sulphur, a low manganese, a phosphorus which is 
within the Bessemer limit, and a titanium. This has 
been passed through a 20-mesh sieve. Sample C gives 
a medium silicon, high sulphur, medium manganese, 
medium phosphorus, and a titanium. This has also 
passed a 20-mesh sieve. Sample D gives a high silicon, 
low sulphur, high manganese, and high phosphorus, 
and has passed through a 40-mesh sieve. 

The standards are sold at the price of $5.00 per 
pound (a discount of 40 per cent, is allowed to colleges 
and dealers), and in no instance will less than one 
pound be sold. The samples are packed in bottles 
holding one-third of a pound and delivered in cases, 
as illustrated on page 189, holding three or four bottles 
according to the desires of a subscriber. One pound 
of the samples should furnish enough material for 36 
complete analyses, or at least 200 separate determina¬ 
tions. The exact analyses of the samples A, B, C, and 
D are sent separately by mail, so that they may be 
placed upon bottles or kept private, as desired by the 
subscriber. 

By addressing any member of the committee (see 
page 183), all orders for drillings will receive prompt 
attention. Money may accompany orders or be sent 
after receipt of drillings, as best suits the pleasure of 
the buyer. 

To secure the first orders for standardized drillings, 

the author found it necessary to call upon many 
managers and chemists at their offices, but the 
good work once well under way advanced so rapidly 



Kidryttien’s ASSCOr 
< D.tZlNO 



JC-M. 

fJiLrf, 


w. 

HUD tfffMf &Hialn«ea $ As 

mr&w®Af*0tz» mc* mJT M 

4 * M "$4 «* m/A< 

TfMJkWSl »l sk «•»•». U fc‘Vt"!.4S|>. (> 

B«p*; 



American FounUrprocn’s rtssoadtion. 


Standardized Sample of Cast Iron. 


The from which the*.’ samnies were taken were made 

by THOS. t). WIST. Their preparation was under the -super, islnn 
of Prof. C. H. Beniamin and Prof. A. v. . Smith. The anolytkal work 
V. a- carried out by Booth, (iarr. i A; Jpalr, Philadelphia, Pa.. Prof. 

A. W Smith, and Cramer 6c Bi. kr.e-ii, of Cleveland. 0., and A. 5. 
IkCtodli, tlarriaburx. Pa. 

NOTICf:. The direction ot the Stamlanlftiag Bureau of the 
American Toundrymen’s Association i» In the care ot Profoaaoia 
C- H. Benjamin and A. W. smith. Case School of Applied Science, 
Cleveland, <J., w ho will arrange for the preparation and distribution 
oi the standardized drilling*. Business communication-- may nleo be ( 


addressed to 


y 


THOS. U. WEST, Chairman, 


SMARPSVItl E. PA. 


? * 


FIG. 47 

























190 


METALLURGY OF CAST IRON. 


that today (Oct., 1901) we have over two hundred 
laboratories in this country and in Europe using these 
standardized drillings. To show the character of 
concerns using these standards, we publish the 
following list in alphabetical order, followed by 
extracts from a few of many testimonials in the pos¬ 
session of the author, which indicate the success of the 
work and the esteem in which it is held: 

Ashland Coal, Iron & Railway Co., Andrew Brothers Co., Alle¬ 
gheny Iron Co., Alabama Consolidated Coal & Iron Co., Andover 
Iron Co., Ashland Steel Co., Atlanta Iron & Steel Co., Allentown 
Rolling Mill Co., Air Brake Co., New York; Atlantic Iron & 
Steel Co., Bellefonte Furnace Co., Brier Hill Iron & Coal Co., 
Buffalo Iron Co., E. & G. Brooks Iron Co., Bethlehem Iron Co., 
Bell City Malleable Iron Co., Builders’ Iron Foundry Co., Lucius 
Brown, Blodgett, Britton & Co., Boulder University, Burgess 
Steel & Iron Works, Bellaire Works, National Steel Co., Canada 
Iron Furnace Co. (Radner Forges and Midland), Colonial Iron 
Co., Chickies Iron Foundry, Carbon Steel Co., Carbon Iron & 
Steel Co., Camden Iron Works, Carteret Steel Co., Carnegie Steel 
Co., Chicago & Burlington Railway, Clinton Iron & Steel Co., 
James Clow & Sons, William Cramp & Sons, J. I. Case T. M. Co., 
Cooper Union, Cornell University, Columbia University, Dunbar 
Furnace Co., Danville Bessemer Co., Dora Furnace Co., Deutsche 
Niles-Werzeugmasschinen-Fabrik, Draper Co., Dickmen & Me- 
Kensie, Dayton Coal & Iron Co., Deseronto Iron Co., Everett 
Furnace Co., Embreville Iron Co., Elk’s Rapid Iron Co., Emma 
Furnace, Empire Steel & Iron Co., Eimer & Amend (four labora¬ 
tories), F. A. Emmerton, Franklin IronWorks, Farrell Foundry & 
Machine Co., Davenport Fischer, Frank-Kneeland Machine Co., 
Fort Wayne High School, The Falk Co., Girard Iron Co., Gates 
Iron Works, E. Grindrod, M. A. Hanna & Co., Hamilton Blast 
Furnace Co., Heckscher & Sons, Hecla Works, England; R. C. 
Hindley, M. Hoskins, Harvard College, Havemeyer University, 
Henry Hiels Chemical Co., Isabella Furnace, Iron Gate Furnace, 
Iroquois Iron Co., Illinois Steel Co., Jefferson Iron Co., Kittan¬ 
ning Iron & Steel Co., C. A. Kelly Plow Co., Lebanon Furnace, 
Longdale Iron Co., Lackawanna Iron & Steel Co., Logan Iron 


ORIGIN AND UTILITY OF STANDARDIZED DRILLINGS. I91 

Mfg. Co., C. E. Linebarger, Ludw. Loewe & Co., Berlin; Lehigh 
University, A. R. Ludlow, Lowmoor Iron Co., Minerva Pig Iron 
Co., Missouri Furnace Co., Monongahela Furnace Co., Mable 
Furnace Co., S. McCreath, McNary & DeCamp Co., Martin Iron 
& Steel Co., Missouri Malleable Iron Co., McConway & Torley 
Co., C. F. McKinney, J. McGavok, Massachusetts Institute of 
Technology, Michigan School of Mines, Northwestern Iron Co., 
New River Mineral Co., Noyes Bros., Sydney, Australia; Nova 
Scotia Steel Co., Niagara University; Nicopol, Mariopol, Sar- 
tana, Russia; Ohio Iron & Steel Co., Oil City Boiler Works, Ohio 
State University, Pickands, Mather & Co., Penn Iron & Steel 
Co., Pioneer Mining & Mfg. Co., Pennsylvania Steel Co., Penn¬ 
sylvania Malleable Co., Pittsburg Locomotive & Car Works, 
Purdue University, Pioneer Iron Co., Princess Iron Co., Punxu- 
tawney Iron Co., River Furnace & Dock Co., Reading Iron Co., 
Rome Testing Laboratory, Sharpsville Furnace Co., Spearmand 
Iron Co., Stewart Iron Co., Salem Iron Co., Shickle, Harrison & 
Howard Co., Sharon Iron Works, Sloss Iron & Steel Co., Syra¬ 
cuse Chill Plow Co., Snow Steam Pump Co., Sargent Co., M. 
Strong, O. Sowers, W. M. Sanders, Stevens Institute of Technol- 
ogy, D. A. Sandburn, Tennessee Coal, Iron & Railroad Co., 
Towanda Iron & Steel Co., Thomas Iron Co., E. Tonseda, Union 
Iron & Steel Co., Union Iron Works, United States Cast Iron & 
Foundry Co. (three laboratories), University of Buffalo, Univer¬ 
sity of Pennsylvania, University of Michigan, University of Min¬ 
nesota, Virginia Iron, Coal & Coke Co., Virginia Polytechnical 
Institute, Warwick Iron Co., Woodward Iron Co., Watt Iron & 
Steel Co., D. Woodman, E. J. Wheeler, Wooster Polytechnical 
Institute, Webster University, Westinghouse Machine Co., 
Wisconsin Malleable Iron Co., Westinghouse Air Brake Co., 
Youngstown Steel Co., Yale University. 


192 


METALLURGY OF CAST IRON. 


EXTRACTS OF TESTIMONIALS IN PRAISE 
OF STANDARDIZED DRILLINGS. 

“We take pleasure in saying that our chemist states he has 
used the standardized drillings in standardizing solutions and 
found them to be very exact; and adds that too much praise 
cannot be accorded the standardized drillings you recently sent 
us. 

Elk Rapids Iron Co., 

H. B. Lewis, Pres.” 

“ It is no little comfort to have the standardized samples and 
to know that the work of our laboratory is correct and reliable. 

Edgar S. Cook, 

Pres. Warwick Iron Co., Pottstown, Pa.” 

“We are pleased with samples. They will, without doubt, 
greatly promote increasing accuracy in methods of iron analysis. 

J. Blodget Britton Co., Warrentown, Va.” 

“We are using the standardized drillings and find them very 
useful in our laboratory. We think it very necessary that labora¬ 
tories should be supplied with standardized drillings, especially 
those working on blast furnace products. L. C. Phipps, 

Second Vice-president Carnegie Steel Co., Pittsburg, Pa.” 

“ It has always been a task to get standards, especially stand¬ 
ards that would check up with those from different concerns. It 
will simplify matters considerably if chemists will use standards 
from one [party of the same value, as I have found that most of 
the errors in sulphur and phosphorus come from different chem¬ 
ists’ standards not checking. J. O. Matherson, Chemist, 

Ashland Coal, Iron & Railway Co.” 

“ I think the method of selling standardized iron samples from 
a central laboratory, such as the Standardizing Bureau of the 
American Foundrymen’s Association, is one to be commended. 
The confidence I have in my work after checking with these drill¬ 
ings is very gratifying. Walter M. Saunders, 

Analytical and Consulting Chemist, Providence, R. I.” 


ORIGIN AND UTILITY OF STANDARDIZED DRILLINGS. 193 

“ In connection with the use of the standardized drillings, I 
wish to say that I believe the plan will result in attaining greater 
accuracy, will inspire confidence, and will enhance the value of 
analytical chemical work in connection with foundry practice. 

W. P. Rickells, 
Columbia University.” 

“ The standard samples are a grand idea and the confidence 
they impart is worth ten times the cost. W. G. Scott. ’ ’ 

“ I have noticed with pleasure your praiseworthy efforts to 
establish uniformity in pig iron analysis. . . . Thanking 

you for your endeavors to mitigate the perplexities of both the 
furnace manager and the chemist, John P. Marshall, 

Supt; Missouri Furnace, Carondelet.” 

“ It is the greatest move for improvement in many years. 

Erastus C. Wheeler,” 

‘‘We have checked our routine laboratory work from time to 
time since receipt of drillings and have found them to be of ines¬ 
timable value to us. Kittanning Iron & Steel Mfg. Co., 

W. L. Scott, Chemist.” 

“ Permit me to express my belief that this work of your asso¬ 
ciation of distributing carefully analyzed samples of pig iron is 
of great value to the metallurgists and chemists of this country. 

H. L. Mills, 

Professor Analytical Chemistry, Sheffield Scientific School of 
Yale University.” 




CHAPTER XXVII. 


INTELLIGENT PURCHASE AND SAMP- 

LING OF PIG IRON. 

There were comparatively few founders using 
chemical analysis in making mixtures of cast iron when 
the first edition of this work appeared, in 1897. At this 
time, Oct., 1901, about three-fourths of the founders are 
dependent upon a knowledge of the chemical constit¬ 
uents of their pig irons, and ignore the appearance of 
fractures or hardness of pig iron. There have been 
some ups and downs in the experience of founders 
working up to the present advancement. Neverthe¬ 
less, as founders come to intelligently understand the 
science of, and methods necessary to be followed in 
working by chemical analysis, they become adherents 
of its practice. One great drawback has been in the 
evils resulting from practices described in Chapters 
XIX. and XXIV., and in the fact of depending 
wholly upon furnace reports of chemical analysis which 
would sometimes prove erroneous by reason of mis¬ 
takes, and cause beginners, in trying to utilize 
chemical analyses to make mixtures, condemn the plan 
of working by analysis. 

It is not safe, as a rule, to depend wholly upon fur¬ 
nace reports of analyses, for the reason that there are 
several chances for mistakes being made aside from 
what the chemists might make. These are mistakes 


PURCHASE AND SAMPLING OF PIG IRON. 


*95 


that may be made in numbering iron piles, transferring 
records of analyses from one book to another, etc., 
and in incorrectly carding the cars when shipping the 
iron to consumers. The author, being surrounded by 
blast furnaces, has seen serious mistakes made in all 
of the above points and is confident that it will pay to 
recognize existing conditions. The only way to 



fig. 48. 

decrease the chance of errors in receiving a furnace 
report of analysis is for the founder to have all such 
reports checked after the iron is received into his yard. 
To do this he should take two or three pieces of pig 
iron from each end, and two or three from the middle 
of every car of iron received, or from the ends of piles 
after it is taken from the car as described on page 140. 
These pieces of pig should be about one-quarter the 
length of a whole pig and drilled after one or the other 
of the plans seen at A, B, and C in Fig. 48. In drill¬ 
ing these samples the utmost care should be taken to 
prevent sand or scale from the pigs getting mixed 


/ 











I96 METALLURGY OF CAST IRON. 

with the drilling's. To prevent this the pigs should be 
thoroughly cleaned with a wire brush before being 
taken to the drill press, where they should be drilled 
with a flat drill, as a twist drill gives a large variation 
in the size of borings according as the hardness of the 
iron varies. Some drill six to ten holes to obtain 
samples as at A, others drill three holes as at B, while 
others drill but one hole in the center as at C. Where 
it is desired to obtain the best possible average of the 
composition of a piece of pig in securing drillings, the 
plan seen at A is followed. It may be said that, as a 
rule, the majority of samples are taken as at C, unless 
analyses of the carbons are required, when it is very 
essential to follow the plan at A or B. In drilling as 
at A or B the material from each hole should be kept 
separate, and after the drilling is completed the same 
weight of drillings from each hole should be taken, 
and the whole mixed together as thoroughly as pos¬ 
sible to obtain an average of the composition of the 
pig. For each analysis about a large teaspoonful of 
drillings is ample, and such are best passed through a 
20- or 40-mesh sieve before being used. To do this it 
may often be necessary to pulverize the drillings in an 
iron mortar. It is very important to properly sample 
a car or pile of iron and take proper precaution in ob¬ 
taining a clean and thoroughly mixed sample of drill¬ 
ings, where one wishes an accurate analysis to show 
the average composition of a car or pile of pig iron. 

The small foundry finds this method, necessary to 
check furnace reports of analyses, objectionable. This 
is on account of such founders not being in a position 
to support a laboratory. However, many small shops 
would find that it would pay them, in the end, to 


PURCHASE AND SAMPLING OF PIG IRON. 


197 


send samples of drillings of every car or pile of iron 
by mail to other localities where a chemist could be 
employed. Unless such shops are doing work of a char¬ 
acter requiring delicacy in making mixtures, analyses 
of the silicon and sulphur are all that they may require 
of their pig metal, and these can be obtained for about 
one dollar for each analysis. This is a small sum com¬ 
pared to the assurance it affords such founders of 
correcting possible errors in furnace analysis reports. 
Many small founders are now beginning to recognize 
this and some are following the above plan and find 
that it pays them well. In cases where a small firm 
could give a chemist other employment they could 
install a laboratory at their own works for one hundred 
to one hundred and fifty dollars, and then, be in a posi¬ 
tion not only to make analyses of their own irons but 
also those of what fuels, blackings, and sand they use, 
when found advisable. 

Another evil of past practices has lain in the founder 
relying upon the furnaceman to advise him of the char¬ 
acter of iron he should use. This is wrong. It is not 
a furnaceman’s business to be responsible for the char¬ 
acter of iron the founder should use, as his experience 
does not rightly afford him such knowledge. All foun¬ 
ders should know their own needs and be able to order 
their irons intelligently. The first two editions of 
this work have achieved much in influencing founders 
to do this. A study of this work should cause the 
moulder or founder who may now look upon chemistry 
as something beyond his comprehension, to talk as 
intelligently and fluently about silicon, sulphur, man¬ 
ganese, phosphorus, and the carbons, etc., in iron, as 
he now can about moulding sand, ramming, venting, 


198 


METALLURGY OF CAST IRON. 


gating, pouring, etc. The grand point about all this 
is the practicability of its achievement by any ordinary 
mind that will make any effort to master this new 
science of founding. 

A description of the methods followed at our foundry 
in Sharpsville, Pa., for delivering pig iron to the 
cupola and keeping a record of our heats, etc., may 
serve many well in giving them ideas to form plans for 
such work. Our pig iron, in being loaded from cars 
or iron piles in the yard, is placed on buggies and then 
pushed to the elevator by a locomotive or hand power, 
after which it is carried to the cupola stage and stored 
in piles after the plan described on pages 141 and 142. 
A record of the silicon, sulphur, etc., contents of each 
pile is kept by the cupola tender, so that he knows just 
what iron to charge. We make a specialty of castings 
that now require heats ranging from seventy to one 
hundred tons weight. Our castings are of such a 
character as to exact certain physical qualities. To 
know that they are right in our castings before leaving 
our shop, we have analyses of the silicon and sulphur, 
and occasionally of the other metalloids made for 
every heat; and when first starting to make these anal¬ 
yses we also conducted physical tests. A plan for 
obtaining both combined is shown by Tables 28 and 29. 
We largely dispense now with the physical test, owing 
to our experience being such as to enable us to judge of 
the physical properties by reason of chemical analysis 
and an examination of the castings. The tests given in 
Tables 28 and 29 were obtained from four round test bars 
cast on end at about equal divisions of the heat. The 
mixture for the heat here recorded was all pig iron, ex¬ 
cepting about 5 per cent, shop scrap, the pig ranging 


PURCHASE AND SAMPLING OF PIG IRON. 199 

from 1.30 to 2.00 per cent, of silicon and from .020 to 
.040 in sulphur. We have an arrangement for our office 
in which a record of the chemical and physical qualities 
obtained in our castings can be recorded. This enables 
us to work intelligently when wishing to refer to past 
results or experiences in repeating old or making new 
mixtures of iron. These records are also kept in such a 
manner as to show the loss in silicon and increase in 
sulphur, etc., in our heats, something which is very es¬ 
sential to be understood, and is treated in Chapter XLV. 

TABLE 28. —PHYSICAL TESTS OF “HEAT” TAKEN SEPTEMBER 14, 1896. 


Rotation 
tests in 
strength. 

Fluidity 

Contraction. 

Deflection. 

Transverse 
strength in 
lbs. 

Chill. 

Diameter 
of test bar. 

Strength per 

sq.inch in 

lbs. 

1 

2 /s" 

•i35" 

.140" 

L955 

8 64" 

i-i43" 

1,907 

2 

2%" 

.130" 

.110" 

1,625 

6 64" 

1.136" 

1,604 

3 

1%" 

.128" 

.120" 

1,520 

5-64" 

1. 130" 

1 5i5 

4 

2 %" 

.124" 

• I 5 0 ' 

L495 

4-64" 

1.142" 

L459 


REMARKS. 

The four test bars showed a perfect, solid fracture. The strongest test 
bar was the last cast and the weakest bar at the second pouring. 

[Signature of Tester.] Thos. D. West. 

TABLE 29. —CHEMICAL ANALYSIS OF STRONGEST TEST BAR. 


Silicon. 

Sulphur. 

Combined 

Carbon. 

Graphitic 

Carbon. 

Phosphorus. 

Manganese. 

1.20 

.079 

.094 

2.67 

.089 

0.40 


CHEMICAL ANALYSIS OF WEAKEST TEST BAR. 


Silicon. 

Sulphur. 

Combined 

Carbon. 

Graphitic 

Carbon. 

Phosphorus. 

Manganese. 

2.15 

,060 

•79 

2-75 

.091 

•37 


[Signature Qf Chemist.] D. K. SMITH, 











































































200 


METALLURGY OF CAST IRON. 


In purchasing pig irons for any new class of work, 

or such as founders are inexperienced with and that 
others may be making, it is often a good plan to find 
out and deal with the furnace which can show dealings 
with founders making the same class of work which 
they desire to manufacture if they can. This starts a 
founder, in making a new class of work, to use brands 
of iron that have been tested and found suitable for 
the class of work he desires to produce, and may be 
the means of preventing some experimenting and loss 
of capital. It was advanced in The Foundry, Nov., 
1901, that buyers of foundry pig iron should consider 
the fracture of pig in being open or close grained in 
connection with specified analyses. How practical 
this proposition is will be found by reference to page 
179. Methods for computing averages of silicon, 
sulphur, etc., that exist in different furnace casts or 
piles of iron, in making mixtures of any special brands 
or different grades, are given in Chapter XXXVI., 
Tables 39 to 42, pages 256 and 257. The net weight 
of sand and chill cast pig iron per ton of 2,268 lbs. and 
2,240 lbs. respectively is given in the first two tables 
at the close of this work. 


PART II. 


CHAPTER XXVIII. 

# 

THE METALLIC AND NON-METALLIC 
ELEMENTS OF CAST IRON. 

Having described processes followed in making cast 
iron and qualities affecting its character, etc., np to the 
time it arrives in pig form at foundries, ready for re¬ 
melting to make castings, as seen in Chapters I. to 
XXVII., we will now treat of qualities which can 
affect cast iron when in the hands of founders, and 
of information which they should possess in order to 
make mixtures best suited for different kinds of gray 
and chilled castings; also on subjects pertaining to 
testing, etc. 

While the effects of silicon and sulphur, manganese, 
phosphorus, and carbon have been referred to some¬ 
what in the preceding chapters, it has only chiefly 
been done in a manner incidental to the manufacture 
of cast iron. It is when pig or cast iron is in the 
hands of founders that its peculiarities or character¬ 
istics are best displayed. For this reason, the second 
part of this work will be found the more important in 
imparting information on cast iron to those em¬ 
ployed in the manufacture of castings or interested 
in their use. In taking up this second part of the 
work, it will be well to first treat of the metallic and 
non- metallic elements of cast iron. 

An element is a substance composed of only one 


ELEMENTS OF CAST IRON. 


203 


kind of atoms. An atom is the smallest sub-division 
of matter which cannot be divided. Every atom is 
exactly like every other atom of the same kind and is, 
as a rule, incapable of independent existence. Atoms 
unite to form molecules, which are the smallest parti¬ 
cles of matter capable of independent existence to 
retain the properties of a mass, and which is any form 
of matter appreciable to the senses. Molecules can be 
formed of one or different kinds of atoms. Where 
molecules are formed of different kinds of atoms, the 
mass is called a compound. There are now about 
seventy different kinds of atoms or elements, among 
which are classed carbon, iron, manganese, phos¬ 
phorus, silicon, and sulphur. Table 130, at the close 
of this work, gives the chemical and atomic weights of 
various elements. 

One method of distinguishing the metallic elements 

or atoms from the non-metallic ones is as follows: Solu¬ 
tions of compounds are sometimes decomposed by an 
electric current. That element which will go to the 
positive pole Is said to be the electro-negative or non- 
metallic, while that element which goes to the negative 
pole is said to be electro-positive or metallic. This divi¬ 
sion of elements among iron workers is more generally 
understood in being classed as metals and metalloids, 
the latter being limited to inflammable non-metallic 
elements, and which as a rule are lighter, bulk for 
bulk, than metals. With this conception of the ele¬ 
ments, we can consider iron, manganese, and silicon 
as being metals, while the carbon, sulphur and phos¬ 
phorus would be classed as metalloids. While this 
classification may be accepted, it is for convenience, 
with founders especially, considered that the term 


204 


METALLURGY OF CAST IRON. 


metalloids shall cover every element in cast iron ex¬ 
cepting the iron. This implies that one or all of the 
elements — carbon, silicon, sulphur, manganese, and 
phosphorus — are classified as metalloids, but it is to 
be remembered that this is incorrect in regard to man¬ 
ganese. To have a clear understanding of the influence 
of these metalloids in affecting the character of iron or 
castings, a study of the following chapters is necessary. 



CHAPTER XXIX. 


CHEMICAL AND PHYSICAL PROPERTIES 

OF CAST IRON. 

Without chemistry we could not define elements 
causing physical effects or be able to scientifically and 
intelligently direct mixtures. The physical test tells 
us what is obtained. The chemical test tells us the 
metalloids we must use to effect results, and each 
property is essential to an attainment of the desired 
end. The first to be noted is carbon, as its influence 
in the form of graphite or combined carbon is the 
greatest in determining the character or “ grade ” of 
cast iron. 

The amount of carbon which iron will absorb depends 
upon the working conditions of a furnace and the 
amount of silicon, phosphorus and manganese taken up 
by the iron. Much silicon reduces the power of iron 
to absorb carbon. The greater the percentage of 
manganese the more carbon can iron absorb, as is 
shown by ‘ ‘ Spiegel ’ ’ iron, which contains carbon as 
high as six per cent. When iron is below .75 in man¬ 
ganese, about 3.50 of carbon is all it contains, although 
it may possess as much as 4.50 per cent, of carbon in 
rare cases. It is claimed that chromium, when sub¬ 
stituted for manganese, will cause iron to absorb carbon 
as high as 12 per cent. The carbon in iron is ob- 


2o6 


METALLURGY OF CAST IRON. 


tained from the fuel used in smelting. The more car¬ 
bon iron contains, the greater influence silicon, etc., 
can have in affecting or changing the “ grade ” of iron. 
The carbon in gray iron is mostly in the form of 
graphite, and the iron may contain as much as three 
to four per cent, of it. Hard or “ white iron ” contains 
carbon in a different state from “ gray iron. ” In white 
iron it is chiefly combined carbon, in which form it 
hardens the iron. The graphitic carbon in gray iron 
can have a large percentage made combined carbon, to 
harden iron, by casting it on a chill or suddenly cool 
ing it. By this action the carbon, which in melted 
iron is in the state of combination, does not have time 
to separate in the form of graphite. 

Combined carbon is ascertained in true chemical ex¬ 
hibits of pig metal by the fracture being small grained, 
of a close, compact nature, and tending to a light gray 
color in Nos. i to 5, and in the higher numbers to a 
white color. The higher its percentage in combined 
carbon, the greater the approach to white iron. The 
faster the iron cools and the more combined carbon it 
contains, the finer the crystals or grain. The lowest 
combined carbon is found in castings having from 
three to four per cent, of silicon, and low in sulphur. 

Graphitic carbon can be told in iron by the fracture 
being large grained and its crystals of a deep, brilliant 
color, from which flakes of graphite can often be ex¬ 
tracted by hand or brushed out. A large percentage 
of graphite in iron will make it very soft, unless re¬ 
tarded by the presence of some hardening substance, 
like manganese. The more slowly a casting cools, the 
more graphite in the iron, and the larger the grain. 
For characteristic determinations of combined carbon 
in a fluid state, see Chapter LX. 


CHEMICAL AND PHYSICAL PROPERTIES, ETC. 


207 


Total carbon is that composing the combined and 
graphitic carbon united. Where the total is known 
and only the combined is stated, the balance necessary 
to make the total would be the graphite, and the 
reverse where the graphite is only known.* 

Woolwich’s experiments have proved that variations 
in the percentage of combined carbon are more effect¬ 
ive in changing the grade of an iron than equal varia¬ 
tions in graphite carbon. A slight increase in graph¬ 
ite, with the combined carbon remaining constant, 
creates very little effect in changing the grade to make 
a softer iron, but if a like change should be made in 
the combined carbon, having the graphite remain con¬ 
stant, the ratio would be greatly changed or the 
‘ ‘ grade ’ ’ of the iron would be very much altered. 

Silicon’s chief office is to soften cast iron and aid the 
founder to regulate or cheapen his mixture. This 
was first suggested by Dr. Percy in the year 1850, 
but it awaited experiments in 1885 by Mr. Charles 
Wood, a founder of Middlesbrough, assisted by Mr. 
John E. Stead, the expert chemist, both of England, to 
first practically demonstrate the value and utility 
of silicon as a softener and its application to found¬ 
ing, a work which, it should be said, had its founda¬ 
tion laid in experiments conducted by Prof. Thomas 
Turner, at Mason College, Birmingham, Eng., the 
same being presented a few months later at the 
Glasgow meeting of the Iron and Steel Institute. The 
extensive publication of this paper is really responsible 
for the universal adoption of silicon as a softener 
in making mixtures of iron. The next to take up 

♦For further information regarding the “total carbon,’’ see 
Chapter XXXIII. 



2o8 


metallurgy of cast iron. 


this work was M. Fred Gautier, of Paris, who, at the 
next spring meeting of the above association, pre¬ 
sented a paper on silicon in foundry iron. These two 
papers started many others experimenting, among the 
most prominent being Mr. W. J. Keep, of Detroit, 
Mich., and the author. 

Not only is silicon a softener of cast iron and an ele¬ 
ment in cheapening the mixture by permitting a large 
percentage of scrap or cheap iron being mixed with 
high-silicon iron, but it is also an element of value in 
increasing the fluidity of metal.* Silicon possesses a 
property which, in a degree, reduces the percentage 
of total carbon which iron may take up, and which also 
can exceed in its percentage any other element in iron. 
It has found such a favor in the estimation of some 
as to make them unregardful of any other element in 
iron, a practice which is decidedly wrong, from the 
fact that one part of sulphur can often neutralize the 
effect of ten to fifteen parts of silicon, and hence for 
this reason it is as essential that the founder should 
be as watchful of sulphur as silicon, and the same 
may be said of the total carbon, phosphorus, and 
manganese, as all should be considered in making mix¬ 
tures ; but the silicon and sulphur should be considered 
the bases for changing the grade or character of iron, 
as seen by Chapter XVII. • 

Silicon can achieve much good, it can also do great in¬ 
jury. It is an element which should only be used with a 
knowledge of the effect any percentage can produce, just 
as a physician can administer a poisonous drug to obtain 
beneficial results. Silicon is a very good thing, so is 


♦Some, to attract attention hare stated that silicon makes iron hard 
and sulphur makes it soft. If iron only had silicon or sulphur in it the 
above would be true, but as we have carbon and other elements in ’cast 
iron it is correct to say, as is stated throughout this work that silicon 

the^carbon < in S the^rcm.^ lari ^ eQS * " Wch is CaUsed bTtheir'^cVng^ 



CHEMICAL AND PHYSICAL PROPERTIES, ETC. 


good whiskey, but either, if not carefully used, can 
cause more evil than good. For this reason, guesswork 
in judging the amount of silicon an iron contains is not 
to be commended. Only by a knowledge of its chem¬ 
ical analysis can constant, uniform or desired results 
in applying silicon to mixtures be best maintained. I 
have found that silicon had a softening effect up to 
about 4.00 per cent., or where it was possible to have 
castings jolted in safety over a pavement or rail track 
in transit for delivery. 

This is as far as the founder ought to go in using 
such “ poison ” to strength. After the carbon has be¬ 
come graphitic all it will, any further addition of sili¬ 
con onty closes the grain and makes the casting “soft 
rotten,” or brittle. If, by still further addition we 
would exceed four per cent, of silicon—which is a per¬ 
centage no ordinary iron mixtures or casting requir¬ 
ing any strength at all should contain—we may then 
harden the iron to a slight degree. A mixture having 
3.75 per cent, of silicon is as high in that element as 
it is practical to use, if we expect general castings to 
hold together, unless the sulphur or manganese is very 
high to harden the iron. It is not desirable to have 
ferro-silicon iron in castings. Very few general 
castings, excepting those for electrical purposes, re¬ 
quire over three per cent, of silicon in their composi¬ 
tion, if the sulphur or manganese is right, and the lower 
the silicon can practically be kept in most castings the 
better the results to be expected from its use. 

In Russia, they have made light castings, as was 
shown in the exhibit at the World’s Fair, 1893, with 
the silicon as low as .55, a little over one-half of one 
per cent., but in order to achieve this, we find the 


210 


METALLURGY OF CAST IRON. 




sulphur did not exceed .022. This is a good ex¬ 
ample in illustration of the effect of sulphur in harden¬ 
ing iron, for had the sulphur been .07, as is generally 
the case as an average for light castings in America, 
with the silicon only .55, such castings would be so 
hard or “white,” that they would never hold together 
long enough for one to handle them. The low sulphur 
in the Russian castings would lead us to say that they 
were made from charcoal or direct furnace iron.* 

Silicon can be absorbed by iron to as high as 20 per 
cent., and from 3 to 4 per cent, of silicon in mixture 
will generally change all the carbon found in ordinary 
irons to graphite that it is possible to change. The 
percentage it will require to do this is dependent 
upon the percentage of the other constituents present 
in the mixture. Silicon ranges from 1 to 5 per cent, 
in Foundry iron, in standard Bessemer iron from 1 to 
2^2 per cent., and in ferro-silicon pig iron from 5 to 14 
per cent. In making mixtures of iron with pig con¬ 
taining 4 to 6 per cent, of silicon there is far less risk 
of over- dosing a mixture than with pig containing 
from 8 to 14 per cent, of silicon, for although we may 
figure out to a nicety just the percentage pig may con¬ 
tain and direct how many pounds should be charged, 
it cannot but be seen that with the higher percentage 
of silicon pig the least error in weighing it, etc., could 
be very disastrous in results. In cases where a found¬ 
er has a cheap class of work and desires to use all the 
scrap, burnt or hard iron possible, he may often iise 

* The Russian analysis was obtained by Mr. H. L. Hollis, of Chi¬ 
cago, and presented in a table with other analyses of American 
castings in a paper read before the Western Foundrymen’s Asso¬ 
ciation, May, 1894. 



CHEMICAL AND PHYSICAL PROPERTIES, ETC. 


21 I 


ferro-silicon pig very economically, or where a foundex 
is running on a specialty of any kind that does not re¬ 
quire different mixtures out of the same heat, with 
good judgment and care, ferro-silicon may often be 
well and profitably applied in mixture.* Four per cent, 
of silicon pig can often carry 80 per cent, of ordinary 
scrap to make soft, machinable castings in work not 
under one inch in thickness. 

Silicon in the pig has a silver cast, and, with some 
grades, a flaky, frost-on-the-window look. It has 
practically no grain and when broken has a fracture 
somewhat like glass. For its appearance in a liquid 
state, see Chapter LX. 

Sulphur in iron is mainly derived from the fuel 
used to smelt it in the blast furnace and in remelting 
it in a cupola. It is the most uncontrollable, injurious 
element the furnaceman or founder has to contend 
with. There are, however, three qualities sometimes 
commendable in it: one is its influence in increasing 
the fusibility of iron, and another its strength, as 
shown in Chapter XXX., and the third its tendency 
to harden or chill iron by reason of its promoting 
combined carbon, which is often better obtained with 
low silicon or high manganese, since with these we 
have less injury from unyielding contraction strains. 
With the exception of the three qualities mentioned 
above, the effects of sulphur are greatly for evil, mak¬ 
ing light castings hard and molten iron sluggish, and 
giving rise to “ blow holes ” in iron solidifying rapid¬ 
ly. It is for these various reasons that charcoal iron, 
on account of its being low in sulphur, has been found 
superior to coke or anthracite iron for many kinds of 
castings. 


* Some keep a stock of ferro-silicon on hand to regulate mixtures in the ab¬ 
sence of their 3.00 to 4.00 per cent, silicon irons, as a little goes a long ways and 
often prevents shutting down for the want of regular irons. 



2 12 


METALLURGY OF CAST IRON. 


With charcoal iron castings we can have low silicon 
without much sulphur, whereas with coke and anthra¬ 
cite iron castings, if we have low silicon, we may 
generally expect high sulphur. Charcoal pig metal 
being the most free from sulphur and impurities, the 
softest strong castings are obtained from it, especially 
when melted in an air furnace. Sulphur is very de¬ 
ceptive in pig metal. It can lurk in hiding so as to be 
present to a much greater degree* than the eye of an 
expert can suspect. For this reason chemical analysis 
is very essential in order to ferret it out. Sulphur can 
cause iron to be red short, as well as cold short. 

Two points of sulphur are more effective in changing 
the character of iron than ten to fifteen points of 
any other constituent which iron possesses. Its influ¬ 
ence in so greatly changing the character of iron is due 
to its ability to radically increase the percentage of 
combined carbon in iron. The alteration that a few 
points in sulphur can effect in the “ grade ” of iron is 
often surprising, and for this reason founders should 
be most watchful of sulphur. The amount of sulphur 
in pig metal generally ranges from .01 for No. 1 iron 
up to .10 for “white iron.” For No. 1 pig metal it 
rarely exceeds 0.03; Nos. 3 to 4, 0.05, and for white 
pig iron 0.10. Sulphur in iron can cause excessive 
shrinkage as well as contraction, the former often be¬ 
ing the cause for shrink holes and the latter for cracks 
in castings.* 

Manganese, when increasing the combined carbon, 

will deepen the chill and cause greater shrinkage and 
contraction, and to a limit greatly strengthens iron. 

*For an article on the effects of sulphur in strengthening iron, 
see Chapter XLIII. 



CHEMICAL AND PHYSICAL PROPERTIES, ETC. 213 

Manganese is readily absorbed by slag and can be car¬ 
ried off as oxide of manganese during a heat, and in 
cupola work will greatly assist in carrying off sulphur 
by means of “ slagging out. ” Manganese ranges from 
a trace up to 3 per cent, in pig iron. The general run 
of good gray pig iron averages about .50; over 1.00 
per cent, it would, in light work, unless proportionately 
higher than 2.50 per cent, in silicon, be injurious in 
causing hard castings, and it is seldom in massive 
work requiring strength that it would be beneficial for 
manganese to exceed 2.00 per cent. Manganese can 
counteract the red shortness caused by sulphur and 
greatly neutralize the effect of sulphur to harden iron 
mixtures. It can be used as a physic to purify liquid 
iron. If the iron is high in sulphur it will be beneficial 
in expelling it and thereby lessen the chances of “ blow 
holes ” by expelling oxides or occluded gases. 

A very peculiar property that has been noticed in pig 
iron containing 2 to 3 per cent, of manganese is that 
while it may look open-grained, like a good No. 1 soft 
iron, it has been found so hard that it could only with 
difficulty be drilled. Manganese gives fluidity and 
life to molten metal, causing it to occupy greater time 
in solidifying. In pig metal, as well as in castings, it 
can cause the crystals to be coarse grained, though 
the iron can be hard, as above stated. 

Manganese is often found as high as 2.50 per cent, 
in foundry pig metal and still make good machinable 
castings. This quality is partly due to the great 
activity which manganese has in expelling sulphur in 
remelting iron. Sulphur is the element of greatest 
power in causing hardness in castings; but,^ on the 
other hand, sulphur can often be so eliminated by man- 


2 T 4 


METALLURGY OF CAST IRON. 


ganese; that for this reason manganese can often be 
high and still soft castings be obtained. The better a 
cupola is fluxed and the higher its temperature, the 
more the manganese will be decreased. In making 
or remelting iron, manganese is affected in a man¬ 
ner somewhat similar to silicon. A hot working fur¬ 
nace will send the manganese into the pig, where a 
cold working furnace will send it into the slag, as it 
requires high heat to make manganese combine with 
the iron, when making it. 

A phenomenon peculiar to manganese is to be cited 
in the opposite results which manganese exerts when 
in the pig, in process of being melted, and when it is 
added as ferro-manganese to soften hard grades of 
molten metal, as is practiced by some founders. The 
author cannot explain the phenomenon better than by 
here inserting comments by Mr. Alexander E. Outer- 
bridge, Jr., in a paper presented by him before the 
Franklin Institute, February 2, 1888: 

A remarkable effect is produced upon the character of hard iron 
by adding to the molten metal, a moment before pouring it into 
a mould, a very small quantity of powdered ferro-manganese, say 
one pound of ferro-manganese in 600 pounds of iron, and thor¬ 
oughly diffusing it through the mass by stirring with an iron 
rod. The result of several hundred carefully conducted experi¬ 
ments which I have made enables me to say that the traverse 
strength of the metal is increased from thirty to forty per cent., 
the shrinkage is decreased from twenty to thirty per cent., and 
the depth of the chill is decreased about twenty-five per cent., 
while nearly one-half of the combined carbon is changed into 
free carbon; the percentage of manganese in the iron is not sen¬ 
sibly increased by this dose, the small proportion of manganese 
which was added being found in the form of oxide in the scoria. 
The philosophical explanation of this extraordinary effect is, in 
my opinion, to be found in the fact that the ferro-manganese acts 


CHEMICAL AND PHYSICAL PROPERTIES, ETC 


2I 5 


simply as a de-oxidizing agent, the manganese seizing any oxygen 
which has combined with the iron, forming manganic oxide, 
which, being lighter than the molten metal, rises to the surface 
and floats off with the scoria. When a casting which has been 
artificially softened by this novel treatment is re-melted, the 
effects of the ferro-manganese disappear and hard iron results. 

In the experiments conducted by the author (seen in 
Chapter XXXII.) he found that, in iron above 2.00 
silicon, the addition of manganese to molten metal had 
a tendency to hold the carbon more in a combined 
form, which is the reverse of its action in low silicon 
irons, and partly in keeping with the above experience 
of Mr. Outerbridge. 

Phosphorus is the element which differentiates 
“ Bessemer” from “Foundry” iron, and generally 
ranges from a trace to 1 ^ per cent, in ordinary pig 
metal. In foundry iron it generally varies from . 25 to 
1.00, and it can be found in iron as high as 7 per cent. 
If iron exceeds .10 in phosphorus it is no longer regu¬ 
lar Bessemer, and may be often classed as Foundry. 
To make this distinction between Bessemer and 
Foundry iron clear, Table 30 is presented: 


TABLE 30 —CHEMICAL ANALYSES OF FOUNDRY AND BESSEMER IRONS. 



No. 1 
Foundry. 

No. 3 
Foundry. 

No. 4 

Bessemer. 

No. 7 

Bessemer. 

Phosphorus. 

.60 

•50 

.09 

.09 

Graphitic Carbon. 

3 50 

3.00 

3-50 

3 CO 

Combined Carbon.. 

•15 

•30 

•35 

•65 

Silicon. 

3.00 

2.25 

2.0D 

1.25 

Sulphur. 

.01 

.02 

.025 

.050 

Manganese. 

•30 

.40 

•50 

•45 


As can be seen by the above table, excepting phos¬ 
phorus, the four analyses could pass as Foundry iron. 
Further comments on Foundry versus Bessemer will 
be found in Chapter XXII. 






















2 l6 


METALLURGY OF CAST IRON. 


Over 0.75 per cent, of phosphorus can cause iron to 
be “cold short,” which means brittle when cold, and it 
may harden iron if used in excess of 1.30 in castings. 

By keeping phosphorus down to between 0.20 and 
0.40, with silicon from 2.50 to 2.75 and sulphur about 
.05, thin castings can often be made so as to bend 
considerably before breaking, and also admit of cast 
iron being readily punched with holes, similarly in some 
degree as wrought iron would be affected by 
like treatment. It has been contended that phos¬ 
phorus is in no wise beneficial to the strength of an 
iron, but Woolwich’s experiments would show that 
phosphorus running from about 0.20 to 0.50 is bene¬ 
ficial in improving the ductile qualities in physical 
tests for cast iron work. Phosphorus is chiefly 
obtained from the ore and flux. It retards the satura¬ 
tion of iron for carbon and adds fluidity and life to 
metal. It is the most weakening element iron can 
possess when used in excess, and is often objectionable 
when it exceeds 1.00 per cent, in Foundry iron, in 
which it is best kept down to not exceed .80. Neces¬ 
sity for extra fluidity, or life, to the liquid metal is 
the only occasion where phosphorus should be permitted 
to exceed .80 in Foundry iron. 

While phosphorus is an element very essential to 
the success of founding, it generally needs to be 
guarded as closely as sulphur or silicon, and an 
intelligent use of it will prove that it can strongly 
influence mixtures and the life and wear of castings. 
The author takes pleasure in citing here some experi¬ 
ences of Mr. James A. Beckett, of Hoosick Falls, 
N. Y., in experimenting in a practical way with 
phosphorus as an agent to regulate actual mixtures 


CHEMICAL AND PHYSICAL PROPERTIES, ETC. 217 

used in a foundry. He writes the author that he has 
found it to greatly counteract the tendency of sulphur 
to increase combined carbon and that he has, upon 
several occasions where high sulphur was giving 
trouble in making castings hard, by increasing the 
phosphorus from 0.50 to 0.75 made castings soft, that 
could not otherwise be machined. Of course, he could 
have attained the same end by increasing the silicon or 
reducing the sulphur, but conditions permitted Mr. 
Beckett to experiment with phosphorus in order to ob¬ 
tain knowledge as to its exact influence when the 
other metalloids were remaining fairly constant. His 
experience in this line is of much value, and it gives 
the author pleasure to record them here, as Mr. Beck¬ 
ett is known to be a good manager. Mr. Beckett’s 
experience in regulating mixtures by phosphorus also 
affirms that generally each tenth of one per cent, in¬ 
crease of phosphorus will give about the same results, 
physically, that an increase of one-quarter of one per 
cent, silicon will give, if the phosphorus is unchanged, 
until the total quantity of phosphorus reaches the limit 
of safety, viz., 1.00 per cent., and that mixtures in 
which the fluidity is increased in this way within such 
limits will be found to produce castings freer from* 
blow-holes and shrink spots than if silicon were entirely 
depended upon for giving fluidity. (See Chap. XXXI.) 

Chromium, as shown by Thomas Turner,* is not 
uncommonly present in small quantities in ordinary 
iron ores. It has been found as high as . 12 in samples 
of pig iron, by J. E. Stead.f It has increased the 
power of iron to absorb carbon up to 12 per cent. 

*Metallurgy of Iron, page 205. 

flron and Steel Institute Journal, 1893, Vol. 1, p. 168. 



2 18 METALLURGY OF CAST IRON. 

Especial alloys of iron and chromium, called ferro- 
chromes, containing as high as 84 per cent, of chromi¬ 
um, are shown by Turner to have been attained. He 
also says that though ferro-chrome is more refractory 
than ordinary cast iron, and is very fluid, it runs 
dead and solidifies rapidly and renders iron hard, white, 
and brittle, behaving in an exactly opposite manner 
from silicon or aluminum. Much more might be said 
of this constituent, but as it has been found up to the 
present time of little value to founding, space is 
reserved for more important elements. 

The constituents of iron, carbon, silicon, sulphur, 
manganese, and phosphorus above described are recog¬ 
nized as the chief elements in controlling the character 
of iron. Aluminum, magnesium, sodium, potassium 
and calcium, as well as titanium, copper, and arsenic, 
are elements found in iron. But of late years little 
note is taken of them by chemists, as they have been 
regarded as having practically little if any weight in 
affecting mixtures or the character of commercial iron, 
and hence we have omitted to discuss their character¬ 
istic qualities to any length in this work. We may 
state that titanium ores were at one time used to some 
extent in obtaining strong iron, but owing to the 
titanic acid of titaniferous ores making an infusible 
slag and causing great trouble in smelting, they were 
seldom if ever used. However, by recent improve¬ 
ment, as seen on page 31, such ores may come more 
into practical use. 

Commercially pure iron, the ideal held up by some 
works to be attained, is not the element iron free 
from every contamination, but iron with about 2 per 
cent, of carbon and free from sulphur, phosphorus, 


CHEMICAL AND PHYSICAL PROPERTIES, ETC. 219 

silicon, and manganese. In getting this iron to a fluid 
condition it will be so full of gas and run so sluggish 
that the casting, if obtained at all, will be full of blow 
holes. Add silicon to this iron and a good sound cast¬ 
ing will result. 

The physical properties of cast iron may be said to con¬ 
sist of density, tenacity, elasticity, strength, toughness, 
brittleness, and chill. These may all differ in having 
characteristic qualities in different brands or classes 
of iron. The first of these elements is to be attributed 
to what is called the “grain,” and the degree of 
density is the basis of grading our iron by fracture 
from No. i (our most open, large-grained iron) up 
through Nos. 2, 3, 4, 5, 6 to 10; the latter two being 
almost as close-grained as a piece of glass, and 
generally called “ white iron.” A cubic foot of white 
iron weighs about sixty pounds more than a cubic 
foot of No. 1 iron. “ White iron ” will sink in a ladle 
of liquid No. 1 iron, whereas a piece of No. 1 would 
float on its surface. 

Tenacity of cast iron is that element which resists a 
pulling apart of its body or a separation of its mole¬ 
cules, as by a tensile strength test. 

Elasticity is that quality which permits cast iron to 
stretch or bend and then return to its original position 
or shape when the load is removed. Should the load 
be so great that the iron will not return to its original 
shape, it partakes of what is called a permanent set, 
or has overreached its limit of elasticity, a point which, 
when attained in cast iron, is very close to the break¬ 
ing load. 


2 20 


METALLURGY OF CAST IRON. 


Average cast iron, when sound, “ stretches about 
.00018, or one part in 5,555 of its length; or inch 
in 57.9 feet for every ton of tensile strength per square 
inch up to its elastic limit, which is at about one-half 
its break strength. The extent of stretching, how¬ 
ever, varies much with the quality of the iron, as in 
wrought iron.”* For further information on the 
stretching qualities of cast iron, see Chapter LV., 
page 422. 

Toughness may be defined as strength, but applies 
more properly to that quality permitting cast iron to 
bend before it breaks, and in transverse testing, such 
is called “deflection.” 

Strength of cast iron is its ability to resist transverse, 
tensile, crushing, and impact blows or strains, and, in 
a sense, includes tenacity, elasticity and toughness. 
It is very rare that castings are designed to resist other 
than transverse or crushing loads. For this reason 
transverse tests are the forms of testing mainly used 
to obtain knowledge of the strength of cast iron, as in 
securing the transverse strength of test bars, we can 
also note the “ deflection,” a quality which tells us of 
the ductility and toughness of iron better than any 
other present method can. Deflection also to a great 
degree informs us of the softness of iron. 

Brittleness is that quality adverse to strength and is 
greatest in “ white ” or “ chilled ” grades of cast iron, 
also high-silicon or phosphorus mixtures. 

Chill is that quality producing a “white” or crystal¬ 
line body in iron. It can be produced by rapid cool¬ 
ing or by having high sulphur or low silicon, which 
produce, in the carbon, a state opposite that of graph* 

* Trautwine. 



CHEMICAL AND PHYSICAL PROPERTIES, ETC. 


22 1 


ite. It is a physical element desirable to exist in 
order to best resist friction surface wear, and is chiefly 
employed in such castings as rolls, car wheels and 
crushers. A special article on the “chill” will be 
found in Chapter LVI. 

Whether the carbon in the iron is combined so as to 
create a “ chill,” or graphitic to make soft or open¬ 
grained iron, largely depends upon the time taken for 
the metal to cool down to solidification, or atmospheric 
temperature. We can take our softest irons, highest 
in graphitic carbon, and by pouring when liquid into 
water cause their carbon to be largely combined 
in the iron; and then, again, we can take our hardest 
or “ white ” irons, that are not high in manganese or 
chromium (qualities seldom to be found in general cast¬ 
ings), and by pouring them into massive castings, like 
heavy anvil blocks, cause their carbon to appear large¬ 
ly of graphite, thus proving that it is chiefly a me¬ 
chanical or physical condition, and not chemical, that 
ofttimes can cause iron to be soft or hard, or present 
peculiarities in its physical qualities. 

The above illustration of pouring liquid iron into 
water and cooling off massive blocks or castings presents 
the radical extremes of any physical effects. In the 
rational, common practice of founding, conditions per¬ 
mit the chemical properties to have a control which com¬ 
pels us to recognize them as the chief factor in dimin¬ 
ishing or increasing the combined carbon or the hard¬ 
ening qualities of an iron. Nevertheless, a study of 
what physical effects can produce will prove to many 
how two castings can often be poured from the same 
ladle of iron so as to have the same percentages of sili- 


222 


METALLURGY OF CAST IRON. 


con, sulphur, phosphorus and manganese exist in the 
two castings, and still have the combined carbon much 
higher in one than in the other. (See pages 167 and 168.) 

Concerning the principles involved in the strength 
of cast iron, we find the most lamentable ignorance 
exists. Some understand that there is such a thing as 
soft and strong grades of iron, but when you have the 
latter practice ignored and the first exacted until the 
product approaches lead, it is time to stop and see 
whither we are drifting. The machine builder, ignor¬ 
ing strength but finding his castings growing softer, 
has encouraged the foundryman in giving such soft 
castings, until to-day many of our machines might as 
well almost be made of so much glass. Such practice 
injures the reputation of cast iron and encourages its 
being replaced by steel, etc. It is not to disparage the 
founder that the author writes of this subject, but if 
possible to awaken thought and action toward a move¬ 
ment by the builders of machinery for the exercise of 
some reason and the attainment of knowledge as to 
where to draw the line at wanting softness at the sacri¬ 
fice of strength. Before the founder knew so much 
about silicon, and had good luck in mixtures, his 
castings would generally show a rich, dark, open frac¬ 
ture, making a .strong, soft casting, instead of being 
found, as to-day with many, in a close, silvery-grained 
grade, making a soft, rotten, leaden casting. 

In using silvery or silicon pig to any extent in mix¬ 
ture there is a very fine line to be drawn in the use of 
just enough to attain the happy medium approaching 
strength and softness. Some would rather take their 
chances of being over the line than under it, and many 
have gone over the line so far as to have castings so 
weak as to break of their own accord. 


CHAPTER XXX. 


AFFINITY OF IRON FOR SULPHUR AND 
ITS STRENGTHENING EFFECTS. 

Owing to a well-known writer having claimed that 
iron does not absorb sulphur, and that the founder has 
no need to fear its existence in castings, the author 
presents this chapter to prove that the contrary condi¬ 
tion prevails. The following tests which the author 
made are such as can be repeated by any one who may 
be desirous of verifying this question: 


TABLE 31 —SULPHUR TEST. 


No. 

of 

Test. 

Quality- 

in 

Casting. 

Micrometer 

Measure¬ 

ment. 

Con¬ 

trac¬ 

tion. 

Deflec¬ 

tion. 

Broke 
at— 
in lbs. 

Chill. 

Strength 
per sq. 
inch. 

18 

19 

Direct bar 
Sulph. “ 

1.100 

1.089 

6- 32 

7 - 32 

.090 

.050 

1385 

i860 

all. 

1457 

1997 


TABLE 32 — CHEMICAL ANALYSIS. 


No. of 
Test. 


Silicon. 

Sulphur. 

Manganese. 

Phosphorus. 


Iron charged. 

.98 

.015 

•30 

.092 

18 

Direct bar. 

•77 

.079 

• 3 i 

.097 

19 

Sulph. bar. 

.86 

•175 

•37 

.097 


Test bar No. 18 is one of four which were poured 
with iron direct from the cupola, with the ladle hold¬ 
ing about 100 pounds of metal. After pouring these 
test bars, about 20 pounds of this metal was then 
poured into a hand ladle, the bottom lining of which 
was composed of fire clay mixed with about two and 






































224 


METALLURGY OF CAST IRON. 


one-half ounces of pulverized brimstone. The 20 
pounds of metal was allowed to stand in the hand ladle 
about forty seconds, when two test bars were poured, 
both of which, when broken, agreed very closely in 
strength. The stronger one of these is recorded as 
test bar No. 19. All of these test bars are of the 
round form and cast on end. It will be seen by a com¬ 
parison of the analysis of these two test bars, Nos. 
18 and 19, that the latter absorbed or contains .096 
more sulphur than the bar which was poured direct 
from the cupola, and .160 more than the iron charged. 
In breaking these bars it will be seen that the high 
sulphur bar No. 19 stood 540 pounds more than the 
direct bar No. 18, thereby asserting that sulphur will 
strengthen iron. But whether or not such an increase 
in strength in test bars could be beneficial to castings 
will depend largely upon the internal strains which 
the addition of sulphur causes in increasing the con¬ 
traction. This can be seen by Table No. 31, in which 
the sulphur bar will be seen to have contracted 1-32 
inch more than the direct bar. I have conducted a 
number of experiments in adding sulphur to the molten 
metal with iron ranging from one per cent, to two per 
cent, of silicon, and have found it to increase the 
strength of the test bars. This is to be expected sim¬ 
ply from the fact that sulphur increases the com¬ 
bined carbon. With two per cent, in silicon in test¬ 
ing one-and-one-eighth-inch round bars, I have 
found it to increase the strength only from 150 to 200 
pounds, thus showing that the higher the silicon, 
the less effect the sulphur has in strengthening the 
iron to the limit of its absorption. Views of the frac¬ 
ture of the above bars, described in Tables 31 and 


AFFINITY OF IRON FOR SULPHUR. 


225 


32, can be seen in Fig. 102, Chapter LX., page 473. 

Iron absorbs sulphur most readily from the fuel 
when being re-melted. I have records of its increasing 
the percentage of sulphur in one re-melt from .030 to 
.105, with fuel below one per cent, of sulphur, and the 
iron charged averaging about 1.60 of silicon. 

It is no uncommon occurrence for iron to be as high 
as three to four per cent, in silicon and to contain as 
high as . 200 in sulphur, thereby proving that iron can 
be high in sulphur and at the same time high in 
silicon. 

While sulphur can increase the strength of iron up 
to a certain limit, it is of such character as to greatly 
decrease resistance to deflection or elasticity of iron. 
On this account I would say that in such castings as 
chill rolls and ingot moulds, which have their surface 
and body subjected to high heat, requiring conditions 
in metal to admit of expansion and contraction follow¬ 
ing each other closely, excessive sulphur is to be 
guarded against, and in light or medium machinery it 
is injurious by increasing the contraction and chill or 
hardness of castings. The former element is injurious 
in causing internal strains, and the latter in causing 
castings to be harder than desired. 

It is now (1901) universally conceded that iron has 
a great affinity for sulphur, and that it is an element 
often to be feared by both furnacemen and founders. 
The distribution of the first two editions of this work 
has done much in advancing the universal recognition 
of these two facts. 


CHAPTER XXXI. 


EFFECTS OF ADDING PHOSPHORUS TO 

MOLTEN IRON. 

This chapter presents results which the author ob¬ 
tained by experimenting with phosphorus added to 
molten iron. Some of these experiments were orig¬ 
inally presented in a paper by the author to 
the Pittsburg Foundrymen’s Association, January, 
1898. In conducting them the metal was caught 
at the cupola in a ladle holding about one hundred 
and fifty pounds. This was carried to the moulds and 
about thirty pounds was poured into a hand ladle into 
which sticks of phosphorus had been placed before 
pouring the metal, and then again by placing the 
sticks on top of the metal. This mixture was stirred 
with a small rod until the phosphorus was thought to 
have been all absorbed." In a natural way phosphorus 
increases the fluidity and life of molten metal, and 
can greatly weaken it. By the above method results 
are reversed and the metal made to lose its fluidity 
and solidify rapidly, and give stronger iron. For 
castings that can be poured with dull metal the ad¬ 
dition of phosphorus may often be very beneficial in 
giving strong castings. The letters P.T. at the left of 
Table 33, page 231, designate the tests having the phos¬ 
phorus added to the metal when in the ladle, and P. B. 
its being placed on the bottom of the ladle and the metal 


EFFECTS OF ADDING PHOSPHORUS TO MOLTEN IRON. 227 

poured onto it, while R. I. refers to the metal free of 
the phosphorus addition. 

All the bars were cast on end and tested 12 inches 
between supports. Those of tests Nos. 1 and 2 were 
made from patterns 1% inches in diameter and the 
balance from i}£ inches diameter. The strength 
column of Table 33 shows the breaking load reduced 
to strength per square inch by the method shown on 
page 476. Each test shown is an average of from two 
to four bars. Tensile tests were made of tests Nos. 1, 
2, 3, 4, 5, and 6. The i^-inch bars with the phos¬ 
phorus addition of No. 1 pulled 27,640 pounds, whereas 
the regular broke at 15,130 pounds, showing that the 
addition of phosphorus nearly doubled the strength of 
the iron in this case. Test No. 3, i}£ -inch bars, aver¬ 
aged 23,790 pounds, whereas No. 4 averaged 17,617 
pounds. Bars of test No. 5 averaged 26,070, and 
those of No. 6 16,890 pounds. A study of Table 33 
will show that all tests were greatly strengthened by 
the slight addition of phosphorus to the molten iron, 
excepting test No. 10. The author believes this is due 
to the high silicon iron. 

A study of the analysis of Table 33 shows that the 
addition of phosphorus drove out or decreased the 
silicon, manganese, and total carbon, the phosphorus 
acting as a flux to drive out oxides or impurities so as 
to leave a greater percentage of metallic iron in the 
higher phosphorus iron than existed in the regular iron, 
as is seen in the last column of the analysis at T. I. 
The effect of decreasing impurities, as shown, is in 
keeping with the treatment of Chapter XXXIV. Aside 
from the decrease of the impurities we find that the 
increase of combined carbon shown, caused by ino-sas- 


228 


METALLURGY OF CAST IRON. 


mg the phosphorus, is also a factor that must have an 
effect in strengthening the iron. The increase of 
combined carbon causes greater contraction but less 
chill, a peculiarity due, no doubt, to the fact that hot 
metal will chill deeper than dull metal, as shown in 
Chapter LVI. However, the ends cast against chills 
were very dense and hard. Tests Nos. i to 6, with 
their analyses, were made by Dr. R. Moldenke at the 
McConway & Torley Co., Pittsburg, Pa., and tests 
Nos. 7 to ii by the author, and the analyses by Mr. 
H. E. Diller at the Pennsylvania Malleable Co., Pitts¬ 
burg, Pa. 

There are several methods of adding phosphorus to 

molten iron. The simplest plan consists in introducing 
the phosphorus with the hand or with tongs. There 
need be no fear of the dampness on the sticks as they 
are taken from the water, for as long as water is on top 
of the metal no harm can result. Care should be taken 
in handling phosphorus by hand to do it quickly, as 
it ignites in a little more than one minute when 
exposed to the air and serious burns'iiave resulted from 
careless handling. Another method used by some is 
to take a rod, to one end of which is secured a dried 
clay or graphitic core having a £4-inch hole extending 
into one end six to seven inches deep. Into this hole 
the phosphorus stick is inserted and held by means of 
sticking a few strips of tin or copper in the vacant 
space. Still another plan is to take a piece of gas pipe 
about three feet long, with a hole a little larger than 
the sticks of phosphorus, and after the phosphorus is 
inserted place a plug of tin about one-eighth of an inch 
thick to fit tightly into the end of the pipe. While 
introducing the end of the pipe into the molten metal 


EFFECTS OF ADDING PHOSPHORUS TO MOLTEN IRON. 229 


the tin will melt quickly and allow the phosphorus to 
diffuse through the metal. To prevent the fumes of 

phosphorus escaping through the upper 
end of the pipe a plug of iron should 
be driven into the pipe some distance 
to permit the insertion of the phos¬ 
phorus. Where several 





FIG. 49, —PAN FOR DRYING 
PHOSPHORUS. 


sticks of phosphorus are 
best inserted in the metal at 
one time,, a device as seen 
in Fig. 50 may often be 
used. After quickly insert¬ 
ing the sticks of phosphorus 
into the receptacle A, Fig. 
50, they are permitted to 
remain a few seconds until dry and showing signs 
of igniting, after which the receptacle is tilted gently 
to slide into the molten metal and held there until 
the phosphorus has been absorbed. A plan fol¬ 
lowed by some to permit sticks of phosphorus being 
handled without danger of taking fire is, to first pre¬ 
pare the sticks by placing them in a dilute solution 
of sulphate of copper, or a few crystals of blue vitriol 
placed in water held in a stone jar, for a period of 
thirty minutes or so. This process deposits a coating 
of copper on the sticks of 
phosphorus, which permits 
them to be handled without 
danger of taking fire as 
long as the copper coating is 

not disturbed. In remov- The space between the iron rod and 

ing the phosphorus from retort is made tight with a cement of 
& . . .. . mineral paint mixed to a stiff paste 

the solution m the jar some with linseed oil. 



0 


FIG. 50. —RETORT 
AND CRUCIBLE FOR 
PHOSPHORIZING. 






















230 


METALLURGY OF CAST IRON. 


place the sticks on blotting- paper resting on wire 
netting, supported in a pan four to six inches deep, 
containing about two inches of water, as shown by 
Fig. 49. This pan should have a cover, which can be 
closed air tight in case the phosphorus takes fire. This 
is a method which was presented by Mr. Max H. Wick- 
horst in a paper before the Western Foundrymen’s 
Association, March 17, 1897. Phosphorus can be ob¬ 
tained from almost any druggist, and comes in the 
form of sticks about three-quarters of an inch in 
diameter and four inches long, weighing about .two 
ounces, and is kept in corked bottles, etc., of water hold¬ 
ing about half-a-dozen sticks of phosphorus. It has to 
be kept in water on account of its being a substance 
which will melt at about in degrees F., and ignite 
of its own accord if left exposed a few minutes to the 
drying influence of the air. 

Another discovery of importance revealed by these 
tests is found in Table 34. This shows that an increase 
of phosphorus increases the fusibility of iron. This 
knowledge is valuable in showing that the lower the 
phosphorus the better, in castings such as annealing 
boxes and pots, ingot moulds, grate bars, etc., which are 
required to stand high temperatures. Up to the time 
the author presented his tests (see Table 34) there was 
no information obtainable designating what percentage 
of the metalloids was best in fire-resisting castings. 
With the information to be gleaned from pages 352 and 
351 it will be seen that the lower the combined carbon, 
sulphur, and phosphorus, the better the iron to resist 
melting or high temperatures. * This knowledge is very 
valuable in assisting to make mixtures for castings that 
are expected to resist high or melting temperatures. 


* For character of iron beat to stand acids see page 291. 



EFFECTS OF ADDING PHOSPHORUS TO MOLTEN IRON. 23 I 


TABLE 33. —COMPARATIVE TRANSVERSE PHOSPHORUS IRON TESTS AND 

ANALYSES. 



Test 

No. 

Defl. 

Str-gt 

Phos. 

Sil. 

Sul. 

Man. 

G. C. 

C. C. 

T. C. 

T. I. 

1st cast, P. T. 

1 

.125 

4.482 

.161 

1.48 

•03 

•65 

2.10 

1.85 

3-95 

6.271 

1st cast, R. I. 

2 

.08 

2.463 

.088 

i -53 

•03 

.68 

2.90 

1.20 

4.10 

6.428 

2d cast, P. T. 

3 

•15 

3,329 

.136 

1.46 

•03 

.58 

1.80 

2.44 

4.24 

6.446 

2d cast, R. I. 

4 

.12 

2,064 

•095 

1.48 

■03 

.60 

2.48 

1.84 

4-32 

6.525 

3d cast, P. T. 

5 

•115 

3.087 

• 173 

1.32 

•03 

•63 

1.84 

2.19 

4 -03 

6.183 

3d cast, R. I. 

6 

.10 

2,170 

•093 

i -37 

•03 

•65 

2.66 

1.50 

4 16 

6.303 

4th cast, P. B. 

7 

•135 

2,322 

.144 

1.20 

.065 

•63 

3-30 

.44 

3-74 

5-779 

4th cast, P. T. 

8 

•125 

2,001 

.121 

1.16 

.068 

.64 

3-37 

•43 

3.80 

5-789 

4th cast, R. I. 

9 

.090 

i. 74 o 

.090 

1.40 

.070 

•65 

3-45 

.40 

385 

6.060 

5th cast, P. B. 

10 

.070 

1.386 

.280 

4 43 

.090 

•36 

2.20 

.82 

3.02 

8.180 

5th cast, R. I. 

11 

.070 

1,366 

.213 

4-45 

.110 

.41 

3-o6 

•03 

3-09 

8.273 


TABLE 34. —COMPARATIVE FUSION TESTS OF BARS RECORDED NOS. I 

TO 6, TABLE 33. 


Diameter of 


1st Cast. 

2nd Cast. 

3rd Cast. 

Rolls. 


iy 2 ins. 

2ins. 

1 y 2 ins. 

2% ins. 

ly ins. 

ins. 

Time of dipping.. 


2:00 

3:00 

2:00 

3:00 

2:00 

3:00 

Time of total 
fusion lower 


2:03% 

3:04% 

2:03 

3:04^ 

2:03^ 

3:05 

phosph’us bars. 
Time of total 
fusion higher 
phosph’us bars, 
DifFer’ce in time 
of melting. 


2:02^ 

3:03^ 

2:02^ 

3 :o 35 f 

2:02 

3:03^ 


1 min. 

1 y min. 

% min. 

iy min. 

1 min. 

1 y min. 


The plan followed in testing the fusibility of the iron 
and phosphorus alloys in Table 34 and shown by Fig. 
51, next page, displays two sizes of fusing test speci¬ 
mens. At H and K, on the left, are bars 1 inches in 
diameter by 12 inches long, connected by a rod M. H 
and K, on the right of Fig. 49, are test specimens 2^ 
inches in diameter by 6 inches long. In casting these 
test specimens one was poured with a regular cupola 
metal, and the other with the metal after the phos- 































































































































































232 


METALLURGY OF CAST IRON. 


phorus had been added in the manner described. By 
using - a hook as at P, to let the test specimens sink 
into a ladle of molten metal, it will be readily seen 
that both bodies H and K must be subjected to exactly 
the same conditions of heat, etc., in testing their fusi- 



fig. 51. 

bility. By such a plan, if H melts down before K we 
have positive proof that H possesses a lower fusing 
point than K. The author has found this a very 
simple and inexpensive plan to test the fusion of mix¬ 
tures, or the effect of any one of the metalloids on the 
fusibility of iron. Another good plan, devised and 
used by the author, is shown in Figs. 87 and 88, pages 
416 and 417. 









CHAPTER XXXII. 


EFFECTS OF VARIATIONS IN MANGANESE 
ON DIFFERENT GRADES OF IRON. 

This chapter presents the results of tests made by 
the author with a wide range of different grades of 
iron, having varying percentages of manganese, to 
give information that will be applicable to nearly all 
classes of founding. The tests far surpass anything 
previously presented for covering a broad field, and 
were originally presented by the author to the Ameri¬ 
can Foundrymen’s Association Convention at Buffalo, 
N. Y., June, 1901. The results shown in Tables 35 
and 36 pages 236 and 237, verify some of the properties 
attributed to manganese and, the writer believes, 
amplify our knowledge of its effect on cast iron 
considerably. We shall first outline the methods of 
physical testing followed in this work. 

The breaking strength and deflection given in col¬ 
umns 3 and 4, Table 35, are each the average of about 
four tests, two of the tests being from ij4-inch 
round bars cast on end, and two from i-inch square 
bars cast flat, and used for obtaining the contraction 
and chill. All bars were tested 12 inches between 
supports. 

The contraction tests recorded in column 5, Table 35, 
were obtained, by casting square bars A and B in a 
frame C, Fig. 52. The contraction was measured by 


234 


METALLURGY OF CAST IRON. 


a graduated wedge D, the thickness of the point at 
which it settled between the bars and frame being 
measured by a micrometer, as at V, Fig. 55. The bars 
were 1 inch square by 24 inches long and poured by 
top gates, as shown. The chill was obtained by break¬ 
ing off a piece at the ends as shown at E, Fig. 55. 

To obtain the hardness tests, the writer arranged a 
drill press, as shown in Fig. 53. A bicycle cyclom¬ 
eter was attached to the upper body of the frame, at 
F, and then a light sheet iron ring was bolted to the 
upper shaft G, with an arm as at H. This arm came 
in contact with the cyclometer at every revolution of 
the shaft G, and recorded the exact number of revolu¬ 
tions made in a stated time, by a watch held in the 
hands of the operator as seen at I. ' In order to apply 
a constant pressure of the drill J on the test piece K, 
a weight L was suspended from the lower arm M, by 
a wire, at a given distance from the end, as shown. 
Three revolutions of the shaft G, equalled two of the 
drill. The machine could be stopped in a second by a 
lever at W. The same ^-inch drill was used for all 
tests, testing the softer specimens first, and the harder 
ones last. The drill was kept of a uniform sharpness 
for the bars of each cast. The drill ran 60 seconds for 
each test and the speed of the shaft G varied from 35 
to 37 revolutions. An average of 36 revolutions was 
allowed in computing the depth of the holes made in 60 
seconds and recorded in column 7.* The tests obtained 
by this drill press proved very satisfactory. To obtain 
the depth of the hole a wooden pin O, Figs. 54 and 55, 
was set into the drilled holes, as seen at P, and a steel 
pin R, pressed into the wooden pin on a level with the 
top of the test specimen, as shown at R. After the 

*hi other words the numbers in column 7 represent the depth of holes 
drilled in 1000 parts of an inch, 

































2 3 6 


METALLURGY OF CAST IRON. 


T" A. BLE 35- 



i 

2 

3 

4 

5 


6 

7 

8 


No. of 
test 

Iron used. 

Breaking 

Strength. 

Deflec¬ 

tion 

Contrac¬ 

tion. 

Chill. 

Hard¬ 

ness. 

Struc¬ 

ture. 

Heat 
No. i 

i.n 

Foundry pig. 

2,169 lbs. 

// 

.107 

.180 

it 

None 

•572 

4 

2. 

Mn. in cupola 

2,268 lbs. 

// 

. I IO 

.231 

II 

None 

.122 

5 

<v o 

3 - 

Foundry pig. 

1,715 lbs. 

II 

.IOI 

. 198 

II 

None 

.625 

5 


4 - 

Mn. in cupola 

.1,808 lbs. 

II 

.082 

.237 

II 

Slight 

• 4 i 5 

5 


5 - 

Charcoal pig. 

1,510 lbs. 

II 

•075 ' 

.276 

II 

None 

OO 

ro 

3 

6 

£ 

6. 

Mn. in cupola 

1,822 lbs. 

ll 

.090 

.291 

II 

None 

.410 

4 

c5 

0» 

33 

7 - 

Mn. in cupola 

1,654 lbs. 

It 

.072 

• 3 i 5 

II 

.025 

.248 

5 

8. 

Mn. in ladle. 

1,577 l bs - 

tf 

.077 

.284 

II 

None 

.506 

2 

tj 

9- 

Foundry pig. 

1,428 lbs. 

*/ 

.IOI 

.125 

II 

None 

•730 

3 

$ o 
33 55 

IO. 

Mn. in cupola 

1,690 lbs. 

n 

»102 

.204 

II 

Slight 

.600 

5 

I I. 

Mn. in ladle 

1,763 lbs. 

.083" 

.161 

II 

None 

•705 

4 


12. 

Foundry pig. 

1,652 lbs. 

11 

.105 

.216 

H 

None 

•553 

3 

U"> 

o 

13 - 

Mu. in cupola 

2,269 lbs. 

n 

.130 

.260 

II 

Slight 

. 107 

6 

w 

14 - 

Mn. in ladle 

1,995 lbs. 

n 

,100 

.229 

ll 

None 

•532 

4 

K 

15 - 

Mn. in ladle 

2,016 lbs. 

n 

.100 

.246 

II 

None 

•578 

4 


16. 

Mn. in ladle 

2,122 lbs. 

n 

.095 

.279 

II 

Slight 

.490 

5 

NO 

17 - 

Foundry pig. 

1,888 lbs. 

u 

. 100 

•309 

II 

None 

•347 

3 

o 

£ 

18. 

Mn. in cupola 

1,794 lbs. 

n 

.097 

.320 

II 

None 

.282 

3 

«-* 

c3 

V 

• 9 - 

Mn. in cupola 

1,845 lbs. 

.080" 

•330 

II 

.062 

.204 

3 

33 

20. 

Mn. in ladle 

1,970 lbs. 

. 102 11 

•309 

II 

None 

• 3*4 

3 


21. 

Charcoal pig. 

2,355 lbs. 

>1 

.095 

•339 

II 

.128 

•385 

7 

o 

22. 

Mn. in cupola 

2,331 lbs. 

n 

.090 

00 

CO 

n 

.166 

•244 

7 

■*-» 

& 

o 

23 - 

Mn. in ladle 

2,394 lbs. 

V 

. 100 

.341 

11 

•055 

•450 

5 

33 

24 . 

Mn. in ladle 

2,310 lbs. 

n 

.102 

.340 

n 

.040 

.428 

5 

Heat 
No.8 

25 - 

Bessemer pig 

1,701 lbs. 

•1 

.125 

.226 

a 

.300 

.420 

3 

26. 

Mn* In cupola 

1,497 lbs. 

ll 

.055 

.242 

n 

All 

White 

White 

o 

27 - 

Charcoal iron. 

1,570 lbs. 

91 

.052 

.401 

11 

1-375 

.040 

Mottled 

o 

£ 

28. 

Mn. in cupola 

1,082 lbs. 

.046 " 

.427 

11 

All 

White 

White 

4-» 

s 

29. 

Mn. in ladle 

1,772 lbs. 

.100 " 

.326 

11 

1.100 

.242 

3 

33 

30 - 

Mn. in ladle 

2,066 lbs. 

II 

•095 

.322 

11 

•830 

.222 

3 


























































9 

10 

11 

12 

»3 

14 

>5 

1 


—" * 

— 

— 1 — 

— 

—- 

- ■ - 

— 

Sil. 

Sul. 

Mang. 

PhoS. 

C.C. 

G.C. 

Total C. 

No. of 
test 

4-53 

.025 

•52 

.194 

.06 

2.98 

304 

1. 

4.40 

.018 

6.12 

.178 

.28 

2.61 

2.89 

2. 

4-51 

•031 

.48 

.203 

.07 

3 -i 9 

3.26 

3 - 

4.41 

•023 

2.62 

.198 

•23 

3.01 

3 -24 

4 - 

4-45 

.110 

• 4 i 

•213 

•03 

3.06 

309 

5 - 

4 - 3 1 

.067 

1.09 

.210 

•05 

3.10 

3 -i 5 

6. 

4 - 3 ° 

.032 

4.09 

.192 

.16 

3-09 

3-25 

7 - 

4-52 

.108 

• 5 1 

.211 

•03 

3-05 

3-°8 

8. 

3-92 

.034 

.44 

.164 

.06 

3-35 

3 - 4 i 

9 - 

3-88 

.029 

1.08 

.156 

.19 

3.16 

3-35 

10 

3-88 

.029 

.76 

. 162 

.08 

3-29 

3-37 

11 

3-88 

.031 

•49 

.194 

.09 

3.06 

3-15 

12 

3-53 

.020 

3-53 

•152 

•30 

2.87 

3 -i 7 

13 

3-82 

s 026 

.68 

• *93 

.11 

3-22 

3-33 

14 

3-62 

.025 

•87 

.191 

.11 

3-39 

3-50 

15 

3-74 

.025 

1.18 

.192 

.10 

3-03 

3-13 

16 

2-47 

.030- 

•97 

.255 

•42 

3-44 

3.86 

17 

2.40 

.022 

2.26 

.250 

•45 

3-38 

3-83 

18 

2.41 

.022 

3-71 

•231 

•47 

3-25 

3-72 

19 

2.56 

.038 

1.16 

•254 

.40 

3-44 

3-84 

20 

1.88 

•039 

.26 

• 458 

.61 

2.92 

3-53 

21 

1.69 

.036 

2-43 

•435 

.64 

2.82 

3-46 

22 

1.89 

•035 

.67 

•455 

•50 

3.02 

3-52 

23 

2.06 

•033 

.78 

•457 

•47 

3 -ii 

3 - 58 * 

24 

»-34 

.076 

•54 

.087 

.61 

3-28 

3-89 

25 

1.30 

,06l 

5 »l 

.076 

3 - 4 » 

•»7 

3-58 

26 

•53 

.070 

•34 

.407 

. 1 .14 

2.66 

3-8o 

27 

.63 

.O42 

2.84 

•365 

3-53 

•»5 

3-68 

28 

.69 

.068 

.69 

.420 

•49 

3 - 4 1 

3-90 

29 

•74 

.060 

•74 

•424 

' .62 

3.28 

3.90 

30 

















































238 


METALLURGY OF CAST IRON. 


pin O was removed it was set on a level clean surface, 
a wedge T passed along until it was stoppd by a pin, 
as at U. The distance the wedge passed under the pin 
U was measured by a micrometer at V, Fig. 55. The 
depth of such holes could also be measured by filling 
them with water and measuring it with a small gradu¬ 
ate, shown at W, Fig. 55. The structure, column No. 
8, is given merely to denote distinctions as made by 
the eye in judging the relative size of the crystals or 
grain of the fracture. For example, No. 2 stands for 
what would be expected of the grain in 1 piece of true 
No. 2 iron, and so on up with closer iron in the higher 
numbers. 

The iron was melted in the twin shaft cupola seen 

in Fig. 56, the operation of which is explained in 
pages 325 to 327. The use of such a cupola is 
the most reliable one for making comparative tests, 
which involve delicate observations and affords a 
remarkably uniform conditions of fuel, blast, heat, etc., 
necessary to discover the true effects of changes in the 
elements composing cast iron. The fact that the tests 
in Table 35 were obtained with the use of the cupola, 
Fig. 56, gives the writer greater confidence in the 
results shown than he could place in any others 
obtained in the ordinary way of making separate com¬ 
parative tests, that is, having one heat taken off one day 
and another some other day, with the differences in 
fuels, blast, and heat conditions that usually exist in 
making heats in ordinary cupolas. 

In charging the cupola, Fig. 56, small pieces from 
the same pig were placed in each compartment and 
the ferro-manganese placed on one side only. For 
the second and fifth heats, shown in Table 35, two 


EFFECTS OF VARIATIONS IN MANGANESE 


239 



FIG. 53 - 



fig. 54. 



































240 


metallurgy of cast iron 



V* 




















EFFECTS OF VARIATIONS IN MANGANESE. 


241 



- A 


0 

y/V 


•v;v. 

r 


r-H 

1 

1 

1 



i.v 

vA?; 

V' 

& 

si'.: 


$ 


.r-r?*;. 

IF 

■*\r 


r 


- 4b 

B 



f.V.: 

■ • ■* • 

@ . 

11 


O 

It 


W 

E 

i 


1 

CO 

r 


^ I 

r 



FIG. 56. 


charges of pig 
iron with differ¬ 
ent percentages 
of m anganese 
were made in the 
side containing 
the manganese. 
The weight of 
the charges was 
from 45 to 60 
pounds of iron 
with a range of 
one to three 
pounds of man¬ 
ganese mixed 
with the charges. 
Heats Nos. 1, 2, 
4, 5, and 6 were 
made of Foundry 
pig iron. Heats 
Nos. 3, 7, and 9 
of Charcoal pig 
iron, and heat 
No. 8 of Besse¬ 


mer pig iron. The analysis of the ferro-manganese 
was silicon 1.65, manganese 80.34, phosphorus .354, 
total carbon 5.85, and no sulphur. 

In adding manganese to the metal in the ladle (this 
metal was always that coming from the side of the 
cupola free from the ferro-manganese mixture), it was 
broken to the size of a pea and thrown gently on top 
of the molten metal, and then stirred well with a half¬ 
inch rod until all melted and in mixture with the iron, 


















































24 2 METALLURGY OF CAST IRON. 

which came down as hot as is generally required for 
pouring stove plate. 

The 210 analyses shown, along with the extra work 
of cross-checking, were made by Mr. H. E. Diller, 
of the Pennsylvania Malleable Co., Pittsburg, Pa. 
The writer and the association are greatly indebted to 
Mr. Diller for his work in making gratuitously such a 
large number of analyses. We have also in this con¬ 
nection to thank Prof. A. W. Smith, of the Case School 
of Applied Science, Mr. Frank L. Crobaugh, proprietor 
and expert of the Foundrymen’s Laboratory, Cleve¬ 
land, O., and D. K. Smith, chemist, Claire Furnace, 
Sharpsville, Pa., for their able services in checking the 
combined and graphitic carbon determinations, a work 
done in order to increase the confidence in the deter¬ 
minations of carbon. 

The moulding, casting, and testing ot the bars were 
all performed chiefly by the writer, as he believes 
experimentors should leave as little to other parties as 
possible. To give an idea of the costs in making 
experiments, it can be said that if the labor and 
material involved in this series of experiments were 
computed at the lowest ordinary rates, the cost would 
reach about three hundred dollars. 

In a general way, the addition of manganese to the 
iron in the cupola increases the hardness by raising the 
percentage of combined carbon, which means greater 
contraction and chill, with a decrease in deflection and 
elasticity. While it is true that manganese in cupola 
mixtures has the tendency just mentioned, a study of 
the tests given in Tables 35 and 36 will show that the 
variation of manganese generally existing in any one 
grade of pig iron will have very little if any effect on 


EFFECTS OF VARIATIONS IN MANGANESE. 


243 


the physical properties of the casting, something which 
is entirely different from the changes 'due to the silicon 
and sulphur of irons coming from any one mixture of 
ores, flux, and fuel. A good test demonstrating this 
point is found in heat No. 6, which has 2.47 silicon in 
Foundry pig when remelted. Here we find that an 
increase from .97 to 2.26 — a difference of over 1.25 
per cent. — of manganese in pieces of the same pig 
does not cause a chill in the ends of the square bars, 
when tested as at E, Fig. 55, and has only a difference 
of .011 in the contraction. By increasing the manga¬ 
nese still higher until we have 3.71 — nearly 3 per cent, 
of an increase — we then obtain a chill of only .062 in 
the ends of the bars, as at E, Fig. 55, and a difference 
of only .021 in the contraction over that found in the 
test bars free of the ferro-manganese mixture. Then 
again, the hardness tests, column 7, show a difference 
of but .065 and .143 in the depth of the drilled holes, 
as at P, Figs. 54 and 55, with the two variations in 
manganese. Still further, the structure, column 8, of 
the gray body exhibits no difference to the eye. 
Another point shown by this heat comes from the 
manganese placed on the molten metal in the ladle. 
Here we find that an increase of .19 in the percentage 
of manganese has made no difference in the contraction 
and a variation of but .033 in the depth in the hardness 
test. This shows that the addition of manganese in 
the ladle tends to slightly increase the hardness, which 
is contrary to what we have generally been led to 
believe by writers in the past. We are not confined to 
this one test to modify views of the past on this point, 
as the same result is also shown in heats Nos. 4, 5, and 
6 . However, when we get to low silicon irons, as in 


244 


METALLURGY OF CAST IRON. 


heats Nos. 7 and 9, we find that manganese in the ladle 
is very effective in softening the iron, or. very sensi¬ 
tive in producing radical changes. 

The effect of manganese on the strength of cast iron 
has a tendency, as a rule, to make iron stronger. In 
adding manganese to molten metal, the iron should 
never be dull, but as hot as practicable, in order that 
all the manganese may be melted in such a manner 
that a homogeneous mixture may result. Where iron 
is dull, a fracture may often show little bright spots 
or grains of manganese alloy that did not melt and 
mix properly with the iron. In such cases more harm 
is done than good. A study of the tests shows that 
the best results for strength were dependent upon cer¬ 
tain percentages of increase. Anything above or below 
this was injurious. The increase of manganese in the 
molten metal ranged from 25 to 60 per cent. The 
effect of adding manganese to molten metal on the 
other elements shows an increase in the silicon and 
decrease in the sulphur, with phosphorus remaining 
fairly constant. With the manganese in the cupola, 
the silicon, sulphur, and phosphorus are decreased. 
The complete Table 36 of analyses affords one excellent 
material for study and information on these points. 

One peculiarity noticed, in making these tests, was 
seen in the high manganese of tests Nos. 2 and 6 caus¬ 
ing the sand to peel most freely from the castings and 
leaving a skin covered with flakes of graphite, whereas, 
with the same iron free from the ferro-manganese 
mixture the sand stuck strongly to the casting. All 
the bars poured with the iron having manganese added 
in the cupola showed this effect to a greater or less 
degree. No doubt this is the cause of some castings 


EFFECTS OF VARIATIONS IN MANGANESE. 


24 $ 


made of the same pattern peeling- much more readily 
than others, with the use of the same grades of sand 
or facing and equal fluidity of metal, a phenomenon 
many have often been at a loss to understand. In 
regard to differences noticeable in the fluidity of the 
metal, there was little if any to be seen between the 
iron coming from either side of the cupola, but the 
addition of manganese to the molten metal in the ladle 
noticeably increased the fluidity. 

Where founders desire a “ white iron ” of the best 
strength obtainable in castings, heats Nos. 8 and 9 
would show that it can be readily obtained by mixing 
ferro-manganese with good strong grades of low silicon 
pig or scrap iron. Of course, white iron can be 
obtained with the cheapest grades of old scrap, but 
this will be much weaker than when good iron and 
ferro-manganese are used. The amount of manganese 
seen in heats Nos. 8 and 9, with the low silicon iron, 
is sufficient to make a casting having a section from 
three to five inches thick all white, when cast without 
the use of chill. Where sections are heavier a greater 
percentage of manganese will be required. It will 
appear rather strange to many to note the high silicon 
charcoal iron used in heat No. 3, as it is rare that such 
brands of iron exceed 2.00 per cent, in silicon. This 
iron was obtained from the Jefferson Iron Co., Jeffer¬ 
son, Texas. The charcoal iron in heats Nos. 7 and 9 
was kindly donated by the Seaman-Sleeth Co., Pitts¬ 
burg, Pa. Further information on the effects of man¬ 
ganese is found on pages 213 to 215. 


CHAPTER XXXIII. 


EFFECT OF VARIATIONS IN TOTAL 
CARBON IN IRON. 

By utilizing the twin shaft cupola shown on page 
241, the author has made comparative tests in several 
different ways, in an effort to discover the effect of 
changes in the total carbon in iron, all other elements 
being held fairly constant. This is a most difficult 
factor to determine, owing to the difficulty of adding 
carbon to iron as can be done with silicon and man¬ 
ganese. The author can now only present opinions 
founded on what might be called indirect tests. These 
tests, in brief, lead the author to say that an increase 
in the total carbon, with all other elements remaining 
fairly constant, increases the life or heat of molten 
metal, softens the iron, increases deflection and 
decreases its strength. Where high carbon exists 
it may cause a kish or scum to rise, which may often 
be the means of producing dirty or porous castings. 
Such results can often be remedied by lowering the 
carbon in mixtures, by the addition of low carbon pig 
metal or steels, etc.* 

It has been suggested that more interest should be 
taken in utilizing the changes in the percentages of car¬ 
bon to effect changes in the grade of an iron, than in 
variations of silicon, as commonly practiced. This is 
an impractical proposition, for the reason that changes 

-The above paragraph shows that the higher the total carbon the less 
shrinkage and contraction and vice versa, other elements being constant. If 
by reason of low carbon there exists excessive shrinkage, the best remedy is to 
mix in higher carbon pig irons, or increase the silicon as well as lower the 
sulphur when possible. 



EFFECT OF VARIATIONS IN TOTAL CARBON. 


247 


in the percentages of carbon in iron cannot be controlled 
sufficiently to regulate mixtures in everyday founding. 
This proposition is largely due to some advocating that 
the creation of the graphitic carbon is not regulated by 
silicon, but due chiefly to changes in the percentages of 
carbon. It is true that the higher the carbon, the more 
graphite there is in normally made and cooled pig iron or 
castings, other conditions being equal. Nevertheless, 
variations in the silicon and sulphur, especially the 
silicon, are chiefly responsible for variations in the 
graphite of different pig or castings. If those who 
think otherwise will take note of variations in the total 
carbon and the combined carbon they will find that, 
allowing for changes in the percentage of total carbon, 
the combined carbon varies closely with those of silicon 
and sulphur, especially the former; or, in other words, 
with a constant total carbon, sulphur, and manganese, 
etc., the higher the silicon, the lower the combined 
carbon and the higher the graphite, in normally made 
and cooled pig iron or castings. 

rialleable founders notice that the heat of iron is 
to some extent dependent upon the carbon in it. As a 
rule the low silicon irons give them the highest carbon. 
When the exception to this rule takes place and they 
get low carbon in low silicon irons, which many prefer, 
they notice its heat effect in a very pronounced manner. 
Iron with less than 1 per cent, silicon may have carbon 
up to 4.50 per cent, while over 4.00 per cent, silicon 
iron may often not exceed 2.00 per cent, carbon. 

To insure good fluidity it is not to be understood, 
by the above, that it is necessary to have carbon above 
3.75. To obtain good fluidity, extra silicon, phos¬ 
phorus, and often manganese are necessary to be com- 


248 


METALLURGY OF CAST IRON. 


bined with the carbon. It is by a proper combination 
of these four elements that the best fluidity and life in 
molten metal is obtained. Very high carbon or silicon 
can cause metal to be sluggish or thick on the surface, 
at either the furnace or foundry. Such iron can often 
be seen evolving a great deal of kish at the furnace, or 
a scum at the foundry, and makes it very difficult, when 
in iron, to obtain clean castings. 

To obtain a thin or clean iron and one which will run 
quickly while it is hot, in making gray castings, use 
a mixture which will give castings having carbon 3.00 
t°3-75> phosphorus .80 to 1.00, maganese .40 to .60, 
silicon 2.50 to 3.00; sulphur to be below .07. Such 
an iron, while running thin as long as it retains its 
heat, could be made softer and have longer life by 
increasing the carbon and silicon above the limits here 
shown, but by doing this the thinness, or quicksilver 
action, would be reduced unless phosphorus was 
increased, which would be liable to make the castings 
brittle. The higher the total carbon, the less silicon is 
required to maintain the grade and the higher can the 
carbon be held in a combined or graphitic state, other 
conditions being equal. See pages 280, 282. 




CHAPTER XXXIV. 


EVILS OF EXCESSIVE IMPURITIES IN 

IRON. 

As a rule cast iron contains 92 to 96 per cent, of 
metallic iron, the balance being impurities such as 
carbon, silicon, sulphur, manganese, and phosphorus. 
While these latter five elements are essential in iron, 
an excess of their total percentages exceeding 6 per 
cent, of cast iron is generally injurious to the best 
strength. To illustrate how an excess of the above 
impurities can weaken iron, the following Table 37 is 
presented. The percentage of impurities and iron 
shown, also the strength tests, are obtained from the 
results seen in Tables 108 to 114, pages 536 and 537. 
By a study of the following Table 37, one should per¬ 
ceive that changes in the total percentages of the 
carbon, silicon, sulphur, manganese, and phosphorus 
can have quite an influence on the strength of castings. 
For example, the chilled roll' mixture (Table 37) 
possessing only 4.803 impurities, as against 6.218 in 
the Bessemer mixture, with others between them 
showing a uniform decrease in strength, demonstrate 
that if the impurities exceed 6 per cent, of the total the 
iron generally decreases in strength according to the 
increase of impurities. One is not to be wholly guided 
by the results presented in Table 37, as any one can 
figure other tests, wherever found, and test the prin¬ 
ciples here set forth. 


250 


METALLURGY OF CAST IRON. 


TABLE 37 — PERCENTAGES OF IRON AND IMPURITIES IN WEAK AND 
STRONG CASTINGS.—SEEN ON PAGES 536 AND 537. 



Chill 

Roll. 

Gun 

Metal. 

Car 

Wheel. 

General 

Machin¬ 

ery. 

Stove 

Plate. 

Bessemer 

Iron. 

Iron.. . 

Impurities.. 

95-197 

4-803 

95.120 

4.880 

94.988 

5 -° 12 

94.100 

5.900 

92-473 

7-527 

93-782 

6.218 

Total . 

100.00 

100.00 

100.00 

100.00 

100.00 

100.00 

Strength of largest 
bar. 

5,013 

4,355 

4,263 

3,786 

3 ,on 

2,860 

Relative strength... 

100. 

87. 

85 - 

75 - 

60. 

57 - 

Relative estimated 
strength. 

100. 

86. 

84. 

77 - 

81.5 

68. 


Impurities in charcoal pig iron are less, as a rule, 
than in coke or anthracite pig iron. This causes the 
“ iron ” to be higher in the former metal. It is now 
conceded that this is a great cause for charcoal irons 
excelling coke or anthracite pig metal in making strong 
castings, when intelligently used. The advantages of 
having high “ iron ” in castings requiring strength are 
illustrated in steel metal. This was ably set forth in 
a paper treating of the importance of having high 
“ iron ” in cast pig metal by the late Captain Henning 
of the Imperial Artillery, Berlin, Germany, before the 
local foundrymen’s association, February 5, 1901, 

wherein he stated that steel castings show only .074 to 
1.44 per cent, of impurities and 98.56 to 99.86 per 
cent. iron. 

The results of the computation of iron as shown in 
Table 37 were first given by Mr. Whitney in a discus¬ 
sion of a paper by the author seen in Chapter LXIX. 
before the Foundrymen’s association, Philadelphia, 
December 2, 1896. During the above discussion Mr. 



















































EVILS OF EXCESSIVE IMPURITIES IN IRON. 


2 5 1 


Whitney dwelt at considerable length upon the practi¬ 
cability of estimating the strength of iron or castings by 
analyses, and was of the conviction that the day was 
not far distant when such would be generally accepted 
as being practical. How closely Mr. Whitney esti¬ 
mated the strength by analysis is shown by the relative 
estimated strength in Table 37. 

The general method of estimating the iron in cast 
metal is by deducting the total of the silicon, sulphur, 
manganese, phosphorus, and carbon percentages from 
100.00. If there have been any errors in figuring 
these various percentages they would, by the above 
calculating process, be then thrown all on to the iron, 
so that as a check to positively determine the iron in 
metal it is really necessary to weigh up the iron after 
the other elements are taken away from it, when 
making the analyses, or make an analysis of the iron 
only and then let such be recorded in a column adjoin¬ 
ing that of the totals for the carbons. Of course, 
wherever the “ iron ” is not shown in analyses it can, 
by the above plan, be estimated as far as such is to be 
valued and thus be made to serve for obtaining the 
“ iron ” contained in any tests. 


CHAPTER XXXV 


CHARACTER OF SPECIALTIES MADE OF 

CAST IRON. 

The following table, No. 38, will afford a fair idea of 
the character of specialties now being made of cast 
iron: 

TABLE 38. 


1. Toys and statuary. 21. 

2. l,ocks and hinges. 22. 

3. Stoves and heating furnaces. 23. 

4. Hollow ware. 24. 

5. Bath tubs. 25. 

6. Furniture castings. 26. 

7. Piano plates. 27. 

8. Dynamos and Electrical Work. 28. 

9. Small pipe fitting and valves. 29. 

10. Radiators. 30. 

11. Pulleys. 31. 

12. Wood-working machinery. 32. 

13. Weaving machinery. 33. 

14. Farming implements. 34. 

15. Molding machines for founding. 35. 

16. Fans and blowers. 36. 

17. Printing presses. 37. 

18. Journal boxes, shaft hangers. 38. 

19. lathes, planers, machine tools. 39. 

20. Street lamps and hitching posts. 40. 


Water and gas pipes. 

Sidewalk grating and manholes. 
Furnace and floor plate castings. 
Sash weights. 

Architectural castings. 

Pneumatic hoists and machinery. 
Gas engines. 

Ammonia freezing machinery. 

Air brakes and railway castings. 
Steam and water pumps. 

Hydraulic cylinders and machines. 
Steam and blowing engines. 

Hand and machine molded gears. 
Mining machinery. 

Punch, shears and dies. 

Ingot molds and stools. 

Annealing pots and pans. 

Cannon, shot and shell. 

Chilled car wheels. 

Sand and chilled cast rolls. 


Aside from the above classifications, there is a great 
variety of light and heavy castings used in different 
forms in the miscellaneous construction and use of 
castings. The list gives us about forty specialties, 





CHARACTER OF SPECIALTIES MADE OF CAST IRON. 253 

many of which call for different grades or mixtures of 
iron and some of which differ very radically. Those 
ranging from Nos. i to 9 generally call for variations 
in what is known as the softest grades of iron. Those 
ranging from Nos. 10 to 22 generally require variations 
in the medium soft grades of iron. No. 23 can gener¬ 
ally be made of harder iron than permissible in the 
numbers above it. No. 24 is generally made of the 
poorest refuse of iron, consisting often of old rusty 
stove plate, burnt grate bars, and annealing pots, also 
tin sheet scrap iron. A mixture of these inferior 
grades generally gives a hard white, or very brittle 
grade of metal. Nos. 25 to 29 are a class of castings 
that will generally require a different mixture and a 
harder iron than those ranging from Nos. 10 to 22. 
Nos. 30 to 35 are specialties which generally call for as 
strong grades of iron as can be finished in lathes, 
planers, etc. Strong grades of iron can be made so 
hard as to make it difficult to turn or plane them in 
finishing such castings. Charcoal iron is often largely 
used in these latter grades, whereas, in Nos. 1 to 29 it 
is rare that such is used, as coke iron can generally be 
made to answer all purposes. Nos. 36 and 37 require 
a grade of iron very distinct from the other specialties 
shown, owing to such castings having to stand radical 
changes of temperatures, which cause an action of 
alternate expansion and contraction while the castings 
are in use. Iron of a medium soft character and low 
in phosphorus, or what is termed regular Bessemer, is 
found best for such castings. The cannon of No. 38 
calls for a grade of iron that should be of fair ductility, 
but at the same time possess the greatest strength to 
be obtained. Cannons are generally made from the 


2 54 


METALLURGY OF CAST IRON. 


best brands of charcoal iron melted in an air furnace, 
which is superior to a cupola in giving the best grades 
of iron for such castings. Nos. 39 and 40 are made of 
what are called chilling irons, and which may be com¬ 
posed of a mixture of charcoal and coke irons, or of all 
charcoal iron. The rolls are best made of iron melted 
in an air furnace, although many are cast with iron 
melted in a cupola. Chilling irons differ most radi¬ 
cally from the grades or brands generally used in the 
specialties Nos. 1 to 38. For information on making 
mixtures for specialties herein described, see Chapters 
XXXVI. to XLIII. pages 255 to 292, 


CHAPTER XXXVI. 


METHODS FOR CALCULATING THE 
ANALYSES OF MIXTURES. 

Some adopting chemistry in making mixtures of 

iron have the impression that iron should come 
from the furnaceman to them possessing the exact 
analysis required for charging. It is rare that furnace- 
men can do this. In our practice, although surrounded 
by blast furnaces from which we may obtain iron, we 
are often compelled to accept two or more different 
grades of extreme variations of silicon, etc., in order 
to make a mixture desired. As a rule, two or three 
different grades will often have to be accepted, espe¬ 
cially by those using a large amount of iron, in order to 
obtain the average which should be charged. (See 
Chapter XXI., page 155.) 

To illustrate methods that will utilize iron of differ¬ 
ent grades as used by the author and others, we will 
suppose that a charge of 2,000 pounds having an aver¬ 
age composition as shown in Tables 39 and 40 is 
desired. These tables show that by a mixture of three 
different grades of iron and two of scrap, an average 
of 2.00 silicon, .032 sulphur, .62 manganese, .435 phos¬ 
phorus, and 3.80 carbon, as shown in Table 41, is 
obtained in the iron to be charged into the cupola 
Another plan is to divide the weight of each kind of iron 
into percentages, after the method seen in Table 42. 


256 


METALLURGY OF CAST IRON 


TABLE 39 — CALCULATING THE SILICON. 


Brand and Grade of 
Iron Used. 

Weight of Iron 
Used. 

Percentage 

Silicon. 

Total Points of 
Silicon. 

No. 1 Flora. 

600 lbs. x 

2.80 = 

1680.00 

No. 3 Clara . 

400 lbs. x 

2.26 = 

904.00 

No. 6 Frank. 

300 lbs. x 

1.50 = 

450.00 

Shop scrap. 

200 lbs. x 

1.80 = 

360.00 

Yard scrap. 

500 lbs. x 

1.25 = 

625.00 


2,000 lbs. 


4019.00 


TABLE 40 — PERCENTAGES OF SULPHUR, MANGANESE, PHOSPHORUS AND 
CARBON IN THE DIFFERENT IRONS. 


Brand and 
Grade of 
Iron Used. 

Weight of 
Iron Used. 

Sulphur. 

Man¬ 

ganese. 

Phos¬ 

phorus. 

T. Carbon. 

No. 1 Flora... 

600 lbs. 

.01 

.60 

•30 

3 50 

No. 3 Clara... 

400 lbs. 

.01 

.70 

.40 

3 -70 

No. 6 Frank. 

300 lbs. 

•03 

.80 

•50 

3-90 

Shop scrap... 

200 lbs. 

•05 

.60 

.40 

4.00 

Yard scrap... 

500 lbs. 

.07 

•50 

.60 

4.10 


TABLE 41 —RESULTS OF COMPUTATION OF TABLES 39 AND 40. 


4019.00 pts. silicon 
64.00 pts. sulphur 
1250.00 pts. manganese 
87.00 pts. phosphorus 
38400.00 pts. carbon 


2,000 lbs. 

= 2.00 

per cent silicon. 

2.000 lbs. 

= .032 

4 4 

sulphur. 

2,000 lbs. 

= .62 

4 4 

manganese. 

2,000 lbs. 

— -435 

4 4 

phosphorus. 

2,000 lbs. 

= 3.80 

4 4 

carbon. 


TABLE 42 — METHOD OF CHECKING TABLE 39. 


Brand and Grade 
of Iron Used. 

Per cent of Iron 
Used. 

Per cent of 
Silicons. 

Total per cent of 
Silicon in 100 
Parts. 

No. 1 Flora. 

30 

X 

2.80 = 

00 

b 

0 

No. 3 Clara. 

20 

X 

2.26 = 

45.20 

No. 6 Frank. 

15 

X 

1.50 = 

22.50 

Shop scrap. 

10 

X 

1.80 = 

18.00 

Yard Scrap. 

25 

X 

1-25 = 

31-25 


100 parts 

= 

200.95 


One part equals about 2.00 per cent of silicon. 

























































CALCULATING ANALYSES OF MIXTURES. 


257 


The total of i.00 parts giving us 200.95 silicon, 
one part will equal about 2.00 per cent, of silicon, the 
same as obtained by the methods shown in Table 39, 
and shows one method to be an excellent check for the 
other. It is true Table 39 only deals with the silicon, 
but it can be seen by Table 41 that its principles will 
also hold good for figuring the percentages of any of 
the metalloids. It will be noticed that in obtaining 
the average percentages of the silicon, manganese, and 
carbon they are figured to the second decimal, and the 
sulphur and phosphorus to the third. 

The grade of scrap iron used is judged by the appear¬ 
ance of its fracture after the plan described in Chapter 
XLII., and the change which takes place in remelting 
the iron to reduce the silicon and manganese and 
increase the sulphur and phosphorus of the mixture 
charged is described in Chapter XLIV. This change 
is such that, with a mixture as per Table 41 and charged 
into a cupola, the resulting castings would contain 
about 1.70 to 1.80 silicon, .05 to .06 sulphur, .45 to .55 
manganese, .48 to .55 phosphorus, and 3.75 to 3.90 
total carbon. 

While for definite calculations Tables 39 to 42 are 

% 

presented, there are cases where one may utilize 
different percentages of silicon, sulphur, etc., by 
mere mental calculation, after the ideas seen on 
page 141, that may answer all practical purposes. 
While the rules of Tables 39 to 42 may appear, at 
first, complicated, to those unaccustomed to such 
computations, they would, with a little practice, soon 
find the methods very simple. 


CHAPTER XXXVII. 


CONSTRUCTION OF CHEMICAL FORMU¬ 
LAS AND EFFECT OF PHYSICAL 
ELEMENTS IN CASTING 
CHILLED WORK. 

Chemistry has proved of greater benefit in making 
mixtures for chilled castings than in any other line. 
When the progressive founder thinks back to the days 
when the chill roll, car wheel, and other manufacturers 
were guided wholly by judgment of fracture in select¬ 
ing their pig metal to make a mixture, he is not at a loss 
to comprehend why such bad results in castings were 
then obtained, accompanied by heavy financial losses. 

In making grey iron castings, there is a much 
greater margin for a divergency from the best point 
to be reached as regards the “ grade ” desired than 
with chilled work. In many cases where soft work is 
wanted it may be found very hard and still be passed, 
or do no injury other than cause extra labor in finish¬ 
ing the castings, etc.; but as a general thing if chilled 
mixtures diverge much from the best point to be at¬ 
tained, the castings will prove worthless by reason of 
“ chill cracks ” or the “ chill-” not be of the depth or 
quality of hardness desired. It is true that most 
chilled work founders would take “chill tests ” of 
their mixture after they had melted their irons. This 


PHYSICAL ELEMENTS IN CHILLING CASTINGS. 259 

would to a great extent be a guide for their next “heat, ’ ’ 
providing the pig metal to be used was exactly the 
same. In melting iron in an “ air furnace ” there is a 
chance to change its composition from what a “ chill 
test ’’ might prove it, before the metal would be tapped 
or poured into a mould; but with cupola work such a 
practice is not permissible. Small cupolas may, in some 
cases, be used to test pig metal before it is used in regular 
cupola mixtures, but analyses are generally a cleaner and 
preferable plan. It is only where analyses cannot be 
obtained or relied on that testing pig metal in small 
cupolas, before being used in regular mixture, is a plan 
which it may, in some cases, be well to adopt. 

The above treatment of this subject is not to be 
taken as decrying the plan of taking “ chill tests ’’ of 
mixture in any or all cases, as such course is advisable 
under all circumstances, since it enables a founder 
having experience to form a close estimate of what he 
has obtained in his castings and assists him to know 
whether a change in the chemical properties would be 
advisable for any following heats. Chilled work will 
always crystallize in planes at right angles to the chill¬ 
ing surface of the iron mould used for chilling the cast¬ 
ing. A standard chill which the author has devised for 
testing the “chill’’of iron can be seen in Chapter LXIX. 

The factors most constant in testing the chill of 
an iron are heat and friction. Heat is the best factor 
for testing the durability of such castings as rolls, and 
friction those like car wheels. It is not to be taken 
for granted, as held by many, that “ white ’’ or chilled 
iron has no degree of hardness or that the depth of a 
chill determines the hardness, for this is not true. 
We may have two castings of exactly the same depth 


260 


METALLURGY OF CAST IRON. 


of a chill or that maybe wholly “ white iron ” and still 
find a difference in the hardness of iron. A good arti¬ 
cle on testing hardness, etc., appears on page 434. 

The success of chilled work is as dependent upon the 
degree of hardness of the chill as upon its depth. One 
set of conditions may exact a harder chill than another, 
and what may prove best in one line of work may be 
a failure in another; as, for example, the same kind 
of chill would not answer as well for paper or calender 
purposes as for steel or iron rolling. Variations in sul¬ 
phur, manganese and phosphorus are chiefly potential 
in giving a special character to the hardness of a chill. 

For “friction wear,” as with car wheel, high sul¬ 
phur will give better life than high manganese com¬ 
bined with low silicon, to cause chill. For “ heat wear, ’ ’ 
hardness or chill is best obtained by high manganese 
in preference to sulphur combined with low silicon. 
Chilled iron is rarely, in any case, a homogeneous mass, 
and sulphur, more than any other element, retards the 
union of the molecules to best attain tenacity in the life 
and wear of iron subjected to heat. While it is true 
that we find in present practice that hardness is gener¬ 
ally obtained by the higher sulphur, as can be seen from 
many of the analyses shown herein, and others recorded, 
still wherever manganese can be applied in preference 
to sulphur, to affect the carbon, in giving hardness to 
chill rolls, etc., better results in preventing surface 
cracks, etc., maybe expected. A chill which is chiefly 
promoted by manganese will prove more yielding to 
strains and not so liable to chill-crack from heat as 
a chill which has been chiefly promoted by sulphur. 

Then again, manganese causes a more gradual de¬ 
cline from the white to the grey in chilled castings 


PHYSICAL ELEMENTS IN CHILLING CASTINGS. 


261 


than does sulphur. It is claimed that this same effect 
is caused by the use of low phosphorus iron, and is so 
radical that it makes the interlacing of the grey and 
chilled bodies very pronounced, as shown in Fig. 57, 
page 264. In referring again to manganese, it can be 
said that its effect to harden is often partly neutralized 
by the sulphur it expels, hence its power to increase 
hardness may sometimes be very small and often call 
for a large increase of manganese before it can produce 
any pronounced effect. 

Professor Ledebur’s division of carbon into four 
states, wherein he describes the elements (as seen in 
Table 44, page 267) existing in carbon as hardening, 
carbide, graphitic, and temper-carbon, is a factor that 
some believe may account, in some cases, for like 
depths of chill not presenting like degrees of hardness, 
also to account for other qualities in physical effects 
which at present are not clearly defined. The pro¬ 
fessor treated this subject in a paper before the 
Iron and Steel Institute, found in their Proceedings, 
No. 2, 1893. Some are of the opinion that the differ¬ 
ences seen in the grain of charcoal from coke iron, 
although the former may carry higher graphitic 
carbon, is due to there being a relatively larger per 
cent, of graphitic temper-carbon in charcoal than in 
coke iron, which is formed while the carbon is in a 
transition state toward graphite. It is unfortunate, 
as stated by Professor Ledebur, that there is no known 
method of analyzing graphitic temper-carbon, or 
that it can only be determined by being estimated 
with the graphite. If this could be determined there 
would be much more interest taken to note its effect 
in castings. 


262 


METALLURGY OF CAST IRON. 


In making chilled work, it is essential to understand 
the various effects which the different metalloids have 
in controlling the combined carbon, associated with a 
knowledge of the individual effect of each metalloid 
in regulating the character of the hardness best calcu¬ 
lated to stand the wear of friction or heat, as outlined 
in the former part of this Chapter. 

In a general way it can be said that the percentage 
of the chemical constituents which combine to make 
chill castings ranges in silicon from 0.50 to 1.10, man¬ 
ganese from 0.55 to 1.50 per cent., phosphorus from 
0.20 to 0.70 and in sulphur from .02 to .10, with the 
total carbon from 2.50 to 3.75. 

The quality to be first understood is the depth of the 
chill and hardness desired in a casting; second, the 
chilling properties of the iron to be used. To make a 
comparative test in order to learn of the chilling quali¬ 
ties of an iron by casting chill specimens, it should be 
remembered that “ hot iron ” will chill deeper than 
“dull iron,’’ and that note should be taken of the 
same, in connection with the other elements of chill¬ 
ing, as outlined in Chapter LYI. It is also to be re¬ 
membered that manganese will give longer life to the 
fluidity of metal than sulphur, where preference can 
be given either, in producing the combined carbon. 
It is very important in assisting to prevent “ cold 
shuts’’ or “ chill cracks,’’ when pouring a mould, to 
have the metal run freely, and hence the advantage 
of manganese over sulphur, as above stated.* 

* Information on the thickness of chills, methods for making 
and pouring “chilled” castings, also making clean and smooth 
and perfect work, can be found on pages 272 and 276 in “Amer¬ 
ican Foundry Practice,” and page 234 in “Moulder’s Text-Book.” 


, CHAPTER XXXVIII. 


MIXTURES FOR CHILLED ROLLS, CAR 

WHEELS, ETC. 

The use of chilled castings has grown to such an 
extent that we find the following chilled specialties 
being manufactured: Rolls for various purposes, car 
wheels, crushers for breaking ore, etc., squeezers for 
balling iron, die presses, anvils, armor for inland 
fortification, shot and shell, axle bearings, grinding 
and grist machinery, switches for railroads, turn-tables 
and transfer plates, boiling pans for various chemical 
purposes, cutting tools, plows, and numerous other 
specialties that might be mentioned to illustrate the 
extent to which the manufacture of chilled castings 
is used. 

In making mixtures for chilled rolls, it is generally 
necessary to consider the thickness through the neck 
and body of the rolls, the thickness of chill desired 
in the castings, and whether they are to be used for 
cold or hot rolling; also the thickness of the chill 
mould used and the temperature of the metal in pour¬ 
ing, as seen by Chapters LI. and LVI. The thickness 
of chill is, in some cases, desired from y 2 to y inch, 
and then again from ^ to i inch. It is rare that more 
than i}( inches thickness of chill is desired in rolls. 
The founder is supposed to have such a control over 
mixtures that he can attain to within a y inch of 


264 


METALLURGY OF CAST IRON. 



the chill thickness desired. Then again, some users 
prefer a sharply defined chill joining the gray body, 
while others prefer the chill and gray body to interlace 
or mingle with each other when combined. This feat¬ 
ure is well displayed in the chilled section of car wheel 
seen at AB, Fig. 57 
Pennsylvania Car 
Wheel Co. of Pitts¬ 
burg, Pa. This factor 
is further treated in 
Chapter XXXVII., 
page 260. 

Chilled rolls for hot 
rolling require differ¬ 
ent qualities than those 
used for cold rolling, 
and are a type of rolls 
subjected to the great¬ 
est abuse. This abuse 
lies in alternate ex¬ 
pansion and contrac¬ 
tion which takes place 
in the outer body of 
the rolls, being sud¬ 
denly heated to about 
500 degrees F. and 
then cooled to the atmosphere. The force of this power 
is often noticeable in remelting rolls in air furnaces, 
where from sudden heating of the outer body they 
will crack, in two or more pieces, with an explosion 
that can often be heard for quite a distance. Rolls 
for hot turning should not only be of such a character 
as to withstand the above alternate strains, but possess 


tendered the author by the 


FIG. 57. —SECTION OF CHILLED CAST 
IRON CAR WHEEL. 



MIXTURES FOR CHILL ROLLS, CAR WHEELS, ETC. 265 

a solid, hard surface free of all defects, that will not 
spawl or shell off by usage, and a depth of chill which 
will permit the face being trued up occasionally until 
the chill is nearly worn off. 

The character of iron used for chilled rolls consists 
largely of cold and hot blast charcoal iron, often 
mixed with broken rolls, car wheels, and sometimes 
steel scrap. Cold blast charcoal combines strength 
with ductility more than any other iron and excels all 
other brands for the manufacture of chilled rolls. Char¬ 
coal iron of Salisbury and Muirkirk brands are 
generally considered as excellent irons for chilled 
rolls, car wheels, etc. Many in making rolls will 
use a good deal of old car wheels and steel 
scrap in their mixtures. For an example, the author 
has used a mixture of 1,300 pounds of old car 
wheels and 300 pounds of steel rail butts for mak¬ 
ing rolls about 14 inches in diameter that required 1 Fl¬ 
inch thickness of chill. Wherever scrap is used in 
mixture with pig, care must be taken to have it of as 
uniform a grade as practical. Another mixture con¬ 
sisted of 1,000 pounds of car wheel scrap, 500 pounds 
of No. 4, and 500 pounds of No. 5 charcoal iron. It 
is to be remembered, wherever we refer to grade num¬ 
bers, that they are supposed to contain silicon and 
sulphur agreeing with table 22, page 152; and by 
referring to the analysis of the car wheel seen on 
page 268 one can perceive about what constituents the 
above scrap should contain. For further information 
on adding steel scrap to iron mixtures and melting it, 
see “ Moulder’s Text-Book. ” Some select car or other 
chilled scrap by the thickness of the chill, but since 
it has become known that the pouring temperature can 


266 


METALLURGY OF CAST IRON. 


vary the depth of a chill in castings, as seen by Chap¬ 
ters LI. and LVI., it is best to be gnided by analyses 
of the grey body of the chilled castings or scrap. 

The impracticability of formulating standard mix¬ 
tures will be realized after a study of the varying 
conditions which must be met in actual practice. Each 
founder must formulate his own mixtures, based upon 
the principles shown in this and the preceding chapter. 
It may be stated that mixtures for chilled rolls, which 
include any scrap used as well as the pig, may often 
range in analysis when ready for charging as per 
Table 43. The wide variations in the sulphur, man¬ 
ganese, and phosphorus seen is given for the purpose 
of showing the range generally necessary to cause 
the different character of chills often required, as seen 
by a study of the preceding chapter. 


TABLE 43—APPROXIMATE ANALYSES FOR CHILLED ROLL MIXTURES. 


Diameter of 
Rolls. 

Silicon. 

Sulphur. 

Man¬ 

ganese. 

Phos¬ 

phorus. 

Total 

Carbon. 

8" to 10" 

1.00 

.01 to .06 

.15 to 1.50 

.20 to .80 

2.60 to 3.25 

12" to 14" 

.80 

.01 to .06 

.15 to 1.50 

.20 to .80 

2.60 to 3.25 

16" to 18" 

.70 

.01 to .06 

.15 to 1.50 

.20 to .80 

2.60 to 3.25 

20" to 22" 

.60 

.01 to .06 

.15 to 1.50 

.20 to .80 

2.60 to 3.25 

24" to 26" 

•50 

.01 to .06 

.15 to 1.50 

.20 to .80 

2.60 to 3.25 


To illustrate Professor Ledebur’s division of carbon 

in rolls, referred to in Chapter XXXVII., page 261, 
Table 44 is given. Iron is melted in both air furnaces 
and cupolas for casting rolls. The air furnace is the 
best for melting such mixtures as it gives a purer 
metal, on account of not compelling the iron to be in 
contact with the fuel when being melted, as it is in 
cupola practice. In melting iron in air furnaces care 
must be exercised to avoid an oxidizing flame, as this 











































MIXTURES FOR CHILL ROLLS, CAR WHEELS, ETC. 267 

can deteriorate the metal and often leave it no better 
than cupola iron. For sand roll mixtures, see page 
273 - 

table 44—ANALYSIS OF TWO ROLLS THAT STOOD WELL. 

BY PROF. A. LEDEBUR. 



Roll 1. 

Roll 2. 

Hardening’ Carbon. 

0.58 

2-43 

0.19 

0-45 

0.46 

1-93 

Carbide Carbon. 

Graphite and Temper Carbon. 


Total Carbon... 

Silicon. 

3.20 

0.83 

0.15 

0.88 

2.84 

0 80 

Manganese. 

Phosphorus. 

0.16 

0.88 

Sulphur. 

0.10 

0.10 



The main difference between mixtures for chilled rolls 
and ear wheels lies in coke iron being used in mixture 
with charcoal iron — or alone, for the latter — and the 
iron being melted in a cupola instead of an air furnace. 
A few have used steel scrap in mixture with pig iron 
for car wheels, but in such cases great care has to be 
exercised to procure a uniform product of steel. The 
more general practice is to depend upon pig iron that 
has been melted in a small cupola to test it physically 
as well as chemically before it is used in the regular 
cupola, where it may be mixed with old car wheels and 
shop scrap. The following Table 45, taken from an 
excellent paper on “ The Manufacture of Car Wheels ” 
by Mr. G. R. Henderson before the American Society 
of Mechanical Engineers, Washington, May, 1899, 
presents the analyses of seven wheels which had given 
from eight to eleven years of service. An analysis ot 
a good wheel by Mr. A. Whitney is also given in 
Table 46. 






















268 


METALLURGY OF CAST IRON. 


TABLE 45. 


Graphitic carbon.2.56 per cent to 3.10 per cent. 

Combined carbon.63 “ “ “ 1.01 “ 

Silicon.58 “ “ “ -68 “ “ 

Manganese.....15 “ “ “ .27 “ “ 

Sulphur.05 “ “ “ .08 “ “ 

Phosphorus.25 “ “ “ .45 “ “ 


TABLE 46—ANALYSIS OF A REMARKABLY STRONG CAR WHEEL. 

BY MR. A. WHITNEY. 


Combined 

Carbon. 

Graphite. 

Manga¬ 

nese. 

Silicon. 

Phosphor. 

Sulphur. 

Copper. 

1.247 

3-083 

0.438 

o .734 

0.428 

0.080 

0.029 


In Tables 47 to 50 we show an analysis of car wheels 
given in a paper by Mr. S. P. Bush before the Master 
Car Builders’ Association, which were obtained through 
the labors of Mr. F. D. Casanave and Dr. C. B. Dudley, 
both of the Pennsylvania Railway Co. In referring to 
these wheels, Mr. Bush says: “Twenty wheels were 
selected from those in service, representing some of 
the principal makes of the country, all of which were 
subjected to the thermal test, ten passing it successfully 
and ten failing. Chemical analyses were made of the 
iron of which these twenty wheels were cast, two sets 
of samples being taken — one from the body, or gray 
iron, and the other from the chill. The result of these 
analyses is as follows: 


TABLE 47—ANALYSES OF THE GRAY IRON. STOOD THERMAL TEST. 


T. C. 

G. C. 

C. C. 

Man. 

Phos. 

Silicon. 

Sulphur. 

3-68 

3.00 

0.68 

0.64 

0.30 

0.56 

0.11 

3-54 

2-74 

0.80 

0.28 

0-47 

0.65 

0.10 

3-50 

3-48 

0.02 

0-35 

0.40 

0-45 

0.13 

3-65 

2.41 

1.24 

0.31 

0-53 

0-57 

0.16 

3-73 

2.89 

0.84 

0.88 

0.38 

0.50 

O.II 

3-63 

3-03 

0.60 

0.44 

0-43 . 

0.56 

0.12 

3-67 

2.70 

0-97 

0.24 

0.38 

0-53 

O.IO 

3-67 

3 -03 

0.64 

0.32 

0.42 

0-47 

0.16 

3-64 

2-53 

1.11 

0-33 

0.50 

0.62 

0.12 

3-86 

3 - 3 i 

0-55 

0.30 

0.36 

0.63 

O.II 



















































































































MIXTURES FOR CHILL ROLLS, CAR WHEELS, ETC. 269 


TABLE 48—DID NOT STAND THREMAL TEST. 


T. C. 

O 

O 

1 

C. C. 

Man. 

Phos. 

Silicon. 

Sulphur. 

3-64 

2.41 

1.23 

0.30 

0-35 

0.71 

0.14 

3.22 

1.98 

1.24 

0-34 

'0.51 

0.77 

0.16 

3 - 5 i 

2.56 

o -95 

0.31 

0.44 

o -75 

0.12 

3-64 

2.30 

i -34 

0.21 

o -39 

0.65 

0.13 

3 - 6 i 

2.52 

1.09 

0.17 

0-35 

0.60 

0.11 

3.61 

2.94 

0.67 

0-33 

0.42 

0.79 

9. 12 

3-72 

2.60 

i-13 

0.23 

0-35 

0.66 

0.11 

3-68 

2-54 

1.14 

0.19 

0-39 

0.88 

0.12 

3-74 

2-57 

1.17 

0.30 

0.41 

0.60 

0.13 

3-45 

2-39 

1.06 

0.40 

0.36 

0.68 

0.19 


TABLE 49 —ANALYSES OF THE CHILLED IRON. 


Stood Thermal Test. 

Did Not Stand Thermal Test. 

Total 

Graphitic 

Com. 

Total 

Graphitic 

Com. 

Carbon. 

Carbon. 

Carbon. 

Carbon. 

Carbon. 

Carbon. 

3-90 

0-43 

3-47 

3 - 9 ° 

0-34 

356 

3 - 7 i 

0.32 

3-39 

3-37 

0.32 

3-05 

3 73 

0.42 

3 - 3 i 

3 - 7 i 

0-43 

3.28 

3 - 7 ° 

0-55 

3 -i 5 

3-75 

0.78 

2.97 

3-87 

0.41 

3-46 

3-74 

0.49 

2.25 

3-77 

0-55 

3.22 

3-77 

0.30 

3-47 

3 84 - 

0-35 

3-49 

3-86 

0 48 

3-38 

3-84 

0.40 

3-44 

3.80 

0.41 

3-39 

3 - 7 i 

0.49 

3.22 

3.82 

0.29 

3-53 

4.01 

0.30 

3 - 7 i 

3-56 

0.36 

3.20 


“These figures cover determinations actually made. 
It was not deemed essential to determine the phos¬ 
phorus, silicon, and manganese in the chills, as there 
was no reason to think that they would differ in propor¬ 
tion from the same elements in the gray iron. In 
reality all borings for the two analyses were obtained 
not over three or four inches apart in the same wheel, 
the one being from the gray iron in the plate and the 
other from the chill. It will be noted that in the gray 
iron the graphite is pretty well toward 3 per cent, and 
































































































































































270 


METALLURGY OF CAST IRON. 


that the combined carbon is toward 1 per cent., while 
in the chill the figures are reversed, the variations 
being not far from one-half of 1 per cent. The figures 
giving the analysis of the gray iron are given for a 
comparison and as a matter of information. 

“The main point in these analyses to which attention 
is called is the close agreement in the composition of 
the chills of these different wheels. If we take the 
averages of those that did and those that did not stand 
the thermal test, we find as follows:” 


TABLE 50. 



Total 

Carbon. 

Graphite 

Carbon. 

Com. 

Carbon. 

Average of wheels which stood the thermal test 

3.81 

0.42 

3-39 

Average of wheels which did not stand thermal 




test. 

3-73 

0.42 

3-31 


“It will be noted that the graphitic carbon is the same 
in both cases, and that the combined carbon only 
differs 0.08 per cent. Furthermore, the general agree¬ 
ment of the combined carbon of the chills in wheels 
from different makers is very noticeable and very 
remarkable. It is difficult to see how any other con¬ 
clusion can be drawn from these figures than that 
there is no evidence, as far as the chemical composi¬ 
tion is concerned, to show that the chills of wheels 
which stand the thermal test differ in their physical 
properties — so far at least as the physical properties 
depend on the chemistry of the metal — from the chill 
of wheels which do not stand the thermal test. Also, 
it seems fair to conclude that wheels made in different 
parts of the country and by different manufacturers 
do not differ very widely so far as chemical composi- 













MIXTURES FOR CHILL ROLLS, CAR WHEELS, ETC. 271 

tion of the chill is concerned. It is quite obvious 
why this should be so, since the chill fixes the chemical 
composition within very narrow limits. ” In conclusion 
Mr. Bush says: “Therefore, to emphasize what has 
been stated previously, it seems reasonable to con¬ 
clude that the wear of car wheels depends upon the 
chill, and if chills of various wheels are so closely alike 
as these analyses show them to be there is really no 
evidence that the wear of these wheels will differ 
to any appreciable extent.” For further analyses of 
car wheels, see Chapter LVII., page 448. 

The sulphur, it will be noticed, is much higher in 
Tables 47 and 48 than in Tables 45 and 46. Sulphur 
from .08 to .15 is now considered by many to give 
long life to car wheel chills. At the same time, it is 
also considered necessary to have manganese range 
from .30 to .80 in order to stand the thermal test 
described in Chapter LVII. This chapter also treats 
of methods of testing mixtures, car wheels, and 
annealing them. The depth of chill required in wheels 
ranges from ^ to ^ of an inch in the throat and y 
to 1 inch at the middle of the thread. Then again, 
there should not be over y of an inch variation in the 
depth of chill in like sections of the rim. In making 
the mixtures, it must be remembered that Tables 45 
to 50 show analyses of the iron after it is remelted or 
in the castings, so that the iron before being charged 
must be higher in silicon and manganese and lower in 
sulphur, after the principle described in Chapter 45. 

Not only has steel and wrought scrap been mixed 
with cast iron pig mixtures, but steel and wrought iron 
scrap may, for some classes of chilled castings, be 
mixed wholly with cast iron scrap, no pig whatever 


2^2 


Metallurgy of cast iron. 


being used. As an example, a mixture of ioo pounds 
of old horseshoes or any kind of light wrought scrap, 
mixed with 1,000 pounds of stove plate scrap, has been 
used to make mould boards for plows and which gave a 
chilled or white iron in the casting. This mixture was 
originally given in The Foundry , March, 1898. A 
study of this chapter in connection with the preceding 
one should permit founders to obtain mixtures for 
almost any line of chilled castings, but it must be 
borne in mind that to obtain the experience to success¬ 
fully make chilled castings has cost founders more 
money, labor, and anxiety than any other line of 
castings. 


CHAPTER XXXIX. 


MIXTURES FOR HEAVY AND MEDIUM 
GRAY IRON CASTINGS. 

Mixtures for heavy gray iron castings may consist 
of all charcoal pig iron or all coke iron; again, these 
pig irons may be mixed in almost any proportion, or 
with scrap. In cases where heavy castings require 
the best possible strength cold or hot blast charcoal 
irons are the best, and one may often have old rails, 
car wheels, steel or wrought scrap mixed with them to 
advantage. In the case of massive castings and utiliz¬ 
ing large, heavy scrap with pig iron, the mixtures are 
generally melted in air furnaces. Cupolas are also 
often used where the scrap is not too large, and some 
obtain excellent strength in iron by their use; never¬ 
theless, as a rule air furnaces should give the best 
results. 

nixtures for sand rolls are generally made of iron 
that is of a hard nature, and in some cases the same 
approximate analysis given for chilled rolls seen in 
Table 43 may be used. Then again, softer mixtures 
may be required than those shown in Table 43, and 
which can be obtained by raising the silicon or lower¬ 
ing the sulphur and manganese as shown. Sand rolls 
are often cast with cupola iron, and such can be made 
to give good service in many cases. 


274 


METALLURGY OF CAST IRON. 


Hixtures for heavy guns should be made of iron pos¬ 
sessing the greatest ductility, combined with strength, 
that can be obtained. Cold blast charcoal iron is the 
best for such castings and should be melted in an air 
furnace. General Rodman obtained from selected 
charcoal pig iron a very strong gun iron which had the 
following analysis: Silicon 1.34, sulphur .003, man¬ 
ganese 1.00, phosphorus .08, graphitic carbon 2.19, 
combined carbon .93. The casting is said to have 
been tough, with a fine granular fracture and a hard 
surface which machined easily; also that its elasticity 
was greatly due to its lowness in phosphorus and 
sulphur. Further analyses of gun mixtures are shown 
on pages 278 and 299. 

flixtures for gun carriages, etc., as given by Titus 
Ulke, M. E., in the Iron Trade Review, December 1, 
1898, are found in the following four paragraphs and in 
Tables 51 to 54: 

1. Castings weighing from 2 to 16 tons were made 
for the United States barbette and disappearing gun 
carriages by the Lorain Foundry Co., at Lorain, O., of 
the following mixtures (Table 51), melted in an air 
furnace, the charge weighing 17 tons: 


table 51. 


\ 

Charcoal iron scrap. 

35 to 45 per cent. 
10 to 20 “ 

Cold blast charcoal iron (Vesuvius and Salisbury). 

Warm blast charcoal iron (Rome and Pine Grove). 

Coke iron (Napier, Dover, etc.) .... 

15 to 25 

20 to 35 “ 



34,000 lbs. 


The average analysis of fifteen heats of the above 
mixture gave silicon .94, sulphur .05, manganese .31, 
phosphorus .44, graphitic carbon 2.40, combined carbon 












MIXTURES FOR HEAVY GRAY IRON CASTINGS. 275 

.63. The average tensile strength is given as 31,350 
pounds per square inch. 

2. In making the chassis rails, base rings, hydraulic 
cylinders, and other parts of disappearing gun car¬ 
riages at the Niles Tool Works, Hamilton, O., the 
following mixture (Table 52), melted in a cupola, 
was used: 

TABLE 52. 


No. 3 Muirkirk charcoal iron. 

5 to 15 per cent, 
3 'A to 15 

25 to 30 “ 

30 

20 To 25 “ 

No. 4^ Muirkirk charcoal iron. 

No. 4 high Uandon charcoal iron. 

No. 4 low L,andon charcoal iron. 

Gun iron scrap. 

Total.. 

100 per cent. 



The analysis of this cupola iron gave silicon about 
1.00, sulphur .05, manganese .6, phosphorus .3, graph¬ 
itic carbon 1.40, combined carbon 1. to 1.20. The 
tensile strength is given as about 33,000 pounds, on an 
average, and the elongation from .5 to .6 of 1 per cent. 
The above Landon iron is made by the Salisbury Car¬ 
bonate Iron Co. (See page 278.) 

3. A mixture made at the Columbus Machine Co.’s 
works, Columbus, O., which gave very satisfactory 
results with the iron melted in a cupola is as follows: 


TABLE 53. 


TVT 1 1 i rir irt rViarooal iron. . .. 

15 per cent. 

25 

20 “ 

30 

10 “ 

Salisbury charcoal iron. 

Tfm'hrrville rote iron niie’h in . 

rtnn iron sorflf). . 

dtppl fhlnntn Ptidsl . 


Total . 

100 per cent. 



The above gun mixture analyzed: Silicon 1.53, sul- 
































276 


METALLURGY OF CAST IRON. 


phur .05, manganese .45, phosphorus .29, graphitic 
carbon 3.01, combined carbon .42, and iron 93.98, 
making a total of 99.74. The tensile strength averaged 
over 30,000 pounds, and the elongation .4 per cent. 

4. In making semi-steel, melted in a cupola at the 
Rarig Engineering Co., near Columbus, O., the follow¬ 
ing mixture (Table 54), was used: 


TABLE 54. ' 


Lawrence pig (No. 2). 

59.3 to 69 per cent. 
39.6 to 30 “ 

.6 to 0.8 “ 

.4 to 0.5 “ 

Homogeneous steel (boiler plate scrap). 

Ferro-manganese, 12 to 15 lbs. per ton.. 

Alloy in ladle, 8 to 10 lbs. per ton. 


Total .. 

100 per cent. 



An alloy composed of the following elements Al. 
2.00, Mn. 8.71, Si. .22, P. .09, Fe. 89.06, which was in a 
granulated form, was put into the ladle to flux the 
metal as described on next page. The analysis of the 
“ semi-steel ” castings gave Si. .98, S. 06, Mn. .43, P. 
.43, G. Car. .96, C. Car. .75. This metal gave an aver¬ 
age tensile strength in three castings of 34,700 lbs. per 
square inch. The castings are said to have been 
found free of blow holes and other defects which are 
sometimes found in semi-steel castings. 

In commenting on “ semi=steel,” so called, Mr. Ulke 
says that it was used as far back as 1873. It was at 
that time made by Mr. Sleeth of Pittsburg, Pa., and 
cast into chilled or dry sand rolls and pinions of superior 
quality. Long before 1873, however, wrought iron or 
steel scrap had been used in making special grades of 
cast iron, such as tough cast iron for drop-hammer dies 
and for similar castings. Certainly the use of steel 
scrap or of similar material in a cupola, or in a ladle is 













MIXTURES FOR HEAVY GRAY IRON CASTINGS. 277 

not a modern or patentable idea. There is no fad or 
physic necessary, although a “ secret ” dope is some¬ 
times used by so-called inventors, chiefly in order to 
throw a veil of mystery over a quite simple process. An 
analysis of one of these expensive “ medicines, ” which, 
however, possibly serves a useful purpose by agitating 
or mixing the metal in the ladle and perhaps reducing 
its sulphur contents, is given in the preceding paragraph. 

“The phenomenal tensile strength (49,000 pounds and 
above) claimed for certain gun iron and semi-steel 
castings is also misleading, if the size and treatment 
of the attached test coupons is not stated, as we shall 
see later. Tests have been and are frequently reported 
as correct — i.e., as fairly representing the pieces the 
physical qualities of which they are intended to deter¬ 
mine—when in reality they are from 3,000 to 10,000 
pounds per square inch too high. This is due to the 
fact that the coupons cast on are only 1 to inches 
round instead of 3 inches, on castings 3 inches in sec¬ 
tion, and therefore chill and harden more rapidly and 
show a correspondingly higher strength than the cast¬ 
ings. ” In conclusion Mr. Ulke says: “The depth to 
which the ‘ chill ’ penetrates, as determined by special 
chill-blocks 6x4x1^ inches in size, cast in special 
moulds in the same heat as the pieces, is a good in¬ 
dication of the tensile strength of the semi-steel cast, 
and serves the foundryman as a simple and convenient 
guide for grading his metal.” 

rielting gun iron mixtures in cupolas has given some 
exceptional results, as will be seen by the excellent 
strengths shown in Tables 52 to 55. These Salisbury 
irons have been used by large concerns, and are spoken 
of in the Iron Trade Review of December 15, 1898, as 


278 


METALLURGY OF CAST IRON. 


having given very satisfactory results. The iron was 
melted with good Connellsville coke in a cupola after 
regular practice. This is a high-priced iron made by 
the Salisbury Carbonate Iron Co., one furnace being 
located at Chapinville, Conn. It is very evident by 
the extract seen below that the Salisbury and Muirkirk 
irons are rivals for the patronage of those making 
strong castings. 

TABLE 55.—TENSILE STRENGTH TESTS OF HIGH GRADE SALISBURY 

CARBONATE IRON. 


Heat Oct. 15th , 1898. Castings in weight from 500 to 18,000 lbs. 

\ Salisbury carbonate iron, No. 4 _ 34,850 lbs. 


Heat Oct. 21, 1898. Castings as above. 

Yz Salisbury carbonate iron, No. 4.. 

“ “ “ No. 4, high. 

Heat Oct. 29, 1898. Castings as above. 

50 per cent Salisbury carbonate, No. 4.. 

30 “ “ “ No. 4, high. 

20 “ “ “ scrap. 


135,320 lbs. 


134,800 lbs. 


Obtaining strong iron from cupolas is a subject which 
interests many, and to have others’ experience than 
the author we give space to an extract of an article pub¬ 
lished in the Iron Trade Review December 29, 1898, 
as follows: “It is probably not known to the trade 
generally that Muirkirk pig iron was the first iron to 
be used successfully in the manufacture of gun iron 
castings for the United States Government, by melting 
in the cupola. Such, however, is the fact; and the 
credit of being able to make gun iron castings in the 
cupola that would stand the tests of the United States 
Government for gun carriage work rightfully belongs 
to Messrs. Robert Poole & Son Co. of Baltimore, Md., 
and Muirkirk pig iron made by me. This was in 1893. 
The War Department at first refused to accept cupola 
iron as gun iron, but when it was fully demonstrated 












MIXTURES FOR HEAVY GRAY IRON CASTINGS. 279 

that the iron was fully the equal of ‘ air furnace gun 
iron,’ they were satisfied. The great strength and 
value of Muirkirk pig iron is not a question of a few 
years, but has been known since the building of the 
furnace in 1841, or over fifty years. Muirkirk was 
used during the Civil War for shot, shell, and cannon. 

It was used in the manufacture of the last cast gun 
iron mortars made for the United States War Depart¬ 
ment, and was used at the United States Navy Yard, 
Washington, D. C., for the manufacture of cast iron ' 
shells until steel was substituted. The fact is that 
until a few years ago there was no-iron that could com¬ 
pete in any way with Muirkirk pig iron for strength 
and elasticity, and now there is none that would be 
preferred at the same price per ton. I have had 
charge of and practically owned this furnace for the 
past thirty-five years. I think I can truly say that I 
never have lost a customer except on account of 
price — never on account of quality. 

Chas. E. Coffin.” 

Muirkirk, Prince George’s County, Md. 

The need of cheap mixtures for medium and heavy 
castings, often calls for the use of coke and anthracite 
irons which carry a large percentage of iron or steel 
scrap. Mixtures are made of these irons that often 
come close to the strength given in Tables 52 to 55 for 
charcoal iron mixtures. Such castings as given in 
Nos. 23, 25 to 35, Chapter XXXV., page 252, are 
largely made of coke or anthracite iron mixed with 
scrap. As much as 80 per cent, of ordinary unburnt 
clean gray scrap iron can be mixed with 20 per cent, 
of 4 per cent, silicon pig iron for many lines of cast¬ 
ings more than 1 ^ inches in thickness, and requiring 


280 


METALLURGY OF CAST IRON. 


to be machined. In castings not requiring a finish, 
such a mixture may be used in castings as thin as 24 
of an inch and still be soft enough to permit being 
chipped in the cleaning. 

The general run of castings ranging from ^ to 4 
inches in thickness, that require to be sufficiently soft 
to be machined and possess similar strength per square 
inch, may often range in analysis of mixtures as seen 
in the approximate Table 56. It is understood that 
these analyses include pig iron and scrap mixed, or pig 
alone, as either mixture would stand ready for charg¬ 
ing. It is not to be expected that the sulphur, man¬ 
ganese, phosphorus, and total carbon can be obtained 
in keeping with the increase of silicon shown. How¬ 
ever, should the sulphur or manganese be increased 
from that shown in the Table, the silicon should be 
increased in such a proportion as to maintain a hard¬ 
ness similar to that obtainable by the analyses shown. 

Should the total carbon be higher than shown for 

the larger thickness then the silicon would require to 

be proportionately lower to maintain similar strengths 

or hardness. It is to be remembered that as a rule the 

total carbon comes highest in low silicon irons, which 

is the reverse of the order shown for carbon in Table 

* 

56, see chapter XXXIII, page 247. 


TABLE 56. —APPROXIMATE ANALYSES OF COKE IRON MIXTURES. 


Thickness 
of Casting. 

Silicon. 

Sulphur. 

Manga¬ 

nese. 

Phos¬ 

phorus. 

Total Carbon. 

w 

2-75 

.02 

•30 

.70 

3.75 to 4.00 

1" 

2.50 

.02 

•30 

•65 

3.50 to 3.75 

w 

2.25 

.02 

.40 

.60 

3.25 to 3.50 

2" 

2.00 

•03 

.40 

•55 

3.00 to 3.25 

2 y*" 

i -75 

•03 

•50 

•50 

2.75 to 3.00 

3 " 

1.50 

•03 

■50 

•45 

2.50 to 3.00 

3 Vi" 

1-25 

.04 

.60 

.40 

2.50 to 3.00 


1.00 

.04 

.70 

•35 

2.50 to 3.00 




























































CHAPTER XL. 

MIXTURES FOR LIGHT MACHINERY AND 
STOVE PLATE CASTINGS. 

Hixtures for light machinery, sewing machines, stove 
plate, hollow ware, and hardware, etc., castings call 
for very soft grades of iron. In making such cast¬ 
ings it is rarely wise to nse any other iron than pig 
and shop scrap. As a rule there is much more shop 
scrap obtained from making light work castings than 
from heavy ones. In light work the shop scrap gen¬ 
erally ranges from 25 to 40 per cent, of the weight 
necessary to be charged for a heat. As melting iron 
hardens it, there must of necessity be sufficient silicon 
added every heat to restore the scrap to the mixture’s 
original softness. For this reason light work shops 
generally find that their own shop scrap is all they can 
wisely use. 

The percentage of silicon in light work mixtures, as 

they stand ready for charging — which includes an 
average of the silicon in the pig and shop scrap — may 
range from 3.00 to 3.80. This would give a silicon in 
the castings resulting from the mixture of such pig 
and shop scrap of from 2.70 to 3.50, according to the 
grade of softness desired in the castings. When the 
silicon exceeds 3.75 in castings the body or surface 
may be often found harder than with lower silicon. 
This is much affected by the percentages of total car- 


282 


METALLURGY OF CAST IRON. 


bon, sulphur, phosphorus, and manganese in the iron. 
The more total carbon the less silicon required, on 
account of carbon softening iron, as can be seen by a 
study of Chapter XXXIII. The following Table 57 
gives an approximate idea of the highest silicon con¬ 
tents it is generally wise to have in soft or light cast¬ 
ings, in combination with the total carbon; the other 
elements, sulphur, manganese, and phosphorus being 
fairly constant at the respective percentages consid¬ 
ered best for making soft castings: 


TABLE 57 - 


Silicon. 

3-75 

3-70 

3-65 

3.60 

3-55 

3-50 

Total Carbon. 

3.00 

3-25 

3-50 

3-75 

4.00 

4-25 


The percentage of sulphur, manganese, and phos¬ 
phorus generally found in light castings is, as a rule, 
.06 to .08 sulphur, .40 to i.00 manganese, and .50 to 
1.25 phosphorus. It will be readily understood, from 
a study of Chapters XXIX. to XXXII., that an increase 
of sulphur and manganese hardens iron, while phos¬ 
phorus increases fluidity and brittleness, and that for 
thin or light castings requiring very fluid metal high 
phosphorus is necessary. As iron for light castings 
must generally be soft, care should be taken not to 
let the sulphur and manganese exceed the above 
amounts in castings. To obtain these percentages 
in castings it will, of course, be necessary to have 
less sulphur and higher manganese in the mixtures 
before being charged, as is explained in Chapter XLV. 

The same regular analyses in different mixtures of 
irons may not give like softness in castings. This 
may be due to the quality described on pages 161 and 
261, or to some brands of iron possessing more of a 













MIXTURES FOR LIGHT MACHINERY, ETC. 283 

chilling quality than others, often due to some special 
peculiarity of the ores from which the iron was made, 
or working of the furnace, and which might often be 
explained were analyses carried beyond determin¬ 
ing the regular five elements. However, it is often 
well for a founder, in starting to make light or stove 
plate castings, to purchase pig iron (after the methods 
described in page 200) from the furnaces that can show 
their irons are being successfully used by other light 
work or stove plate foundries. 

If any yard or foreign scrap iron is used, care should 
be taken to have it clean and free as possible from rust 
or oxide of iron; also, no burnt iron should be used, 
as such will greatly cause mixtures to give hard iron 
in light work. (Facts treated further in pages 295 
to 297.) The best test for softness in light work 
castings generally lies in the castings themselves, 
as almost every light casting if not of a sufficiently 
soft character is readily told by means of a file, grind¬ 
stone, or chisel. If light castings crack, it is generally 
evidence of the iron being too high in sulphur or phos¬ 
phorus, or too low or high in silicon, which latter can 
be told readily by an examination of the fracture, as 
if they are too low in silicon the edges of the casting 
will show a greater chill than from an excessive use of 
silicon. Then again, the latter will give a very brittle 
body, while the former will be of a stronger character. 
It is to be remembered that there is a limit to the use 
of silicon in affording softness, and that it can make 
very brittle castings, as shown on page 209. 


CHAPTER XLI. 


MIXTURES AND ELEMENTS DESIRABLE 
FOR ELECTRICAL WORK. 

Castings for electrical work were supplied by our 
foundry for several years to a leading manufacturer. 
It was with much surprise that we found, when first 
commencing this work, that no one in the plant using 
our castings knew what chemical properties were es¬ 
sential to exist in their dynamos, other than that the 
buyer wanted them soft, as it was found that a hard 
metal resisted the action of the current and did not 
form a good magnetic conductor. To give an idea of 
what properties are essential in castings for electric 
work, the following analyses of drillings which were 
taken from a dynamo casting for the author, which had 
proven to possess good electrical induction or magnetic 
permeability, is presented: * 

TABLE 58.—CHEMICAL ANALYSIS OF DYNAMO IRON. 


Silicon. 

Sulphur. 

Phos¬ 

phorus. 

Manga¬ 

nese. 

Graph. 

Carbon. 

Comb. 

Carbon. 

Total 

Carbon. 

3.190 

•075 

.890 

•350 

2.890 

.060 

2.950 


A study of the above analysis will show the product 
to be a very soft iron, which in a general sense covers 
the requirements; and when it is said that all elements 
should be avoided which favor the formation of com¬ 
bined carbon, the founder has a key to guide him in 

*For the relative conductivity of different metals for heat and 
electricity, see Table 135, page 593, 



















ELEMENTS DESIRABLE FOR ELECTRICAL WORK. 285 

making 1 mixtures for castings expected to convey elec¬ 
tric currents. 

It will be seen that the silicon in the above analysis 
is as high as 3.190, a point rarely attained in other 
specialties of casting, but it will be noticed that the 
sulphur is also well up, so that it greatly neutralizes 
the softening effect of the silicon. If the sulphur 
were about .050, the same softness would be obtained 
with about 2.60 of silicon, so powerful is the effect of 
a few points in sulphur to promote combined carbon. 

In testing a casting to discover its degree of softness 
by analysis, it is usually best to first find its percent¬ 
age of combined carbon, which should not exceed .70 
and is best kept down, if possible, to about .30. If an 
analysis shows the combined carbon to be too high, 
then determinations should be made of the sulphur 
and silicon contents of the iron, to learn if either of 
these elements is at fault, as these properties are the 
bases in changing the “ grade ” of iron to control the 
carbon in taking the graphitic or combined form. 
The higher the carbon, and the more it is thrown into 
the graphitic form, the better the iron for electric work. 

The effect of high phosphorus is to slightly re¬ 
tard softness, and for this reason it is also best kept 
as low as is consistent in obtaining the fluidity de¬ 
sired. Phosphorus should not exceed .80, unless 
some very thin castings are to be made, or there are 
parts in heavy castings difficult to “ run;'” then phos¬ 
phorus may be allowed to approach 1.00. 

Manganese in iron for electric work is also a factor 
which requires watching, as its tendency is to promote 
hardness or combined carbon. It is best not to 
exceed .30, unless the silicon is over 3.00 and the 


286 


METALLURGY OF CAST IRON. 


sulphur under .060, then the managanese might be per¬ 
mitted to go higher. Manganese is somewhat decep¬ 
tive, as it will permit a casting to arrange its crystals 
in large grains, giving the iron the appearance of be¬ 
ing high in graphite when at the same time the metal 
is much harder than if the large grains were all the 
result of silicon in giving the iron large grains. 

By a study of this Chapter it will be observed that 
the state of the combined carbon is the chief factor in 
determining the utility of a casting for electrical pur¬ 
poses. We have stated that it is desirable that com¬ 
bined carbon should not exceed .70 in any casting. It 
is to be remembered that the thickness of a casting 
and the time it takes the molten metal to solidify 
have also a great influence in determining what per¬ 
centage of combined carbon a casting will contain. 
The more quickly a casting cools the higher will be its 
percentage in combined carbon. For this reason it will 

m 

be evident that thin castings would require higher silicon 
and lower sulphur, also manganese, than thick castings. 

With all the above elements to influence the forma¬ 
tion of combined carbon, it is evident that it would 
not be practical to here attempt to prescribe what per¬ 
centage of sulphur and silicon a mixture should con¬ 
tain. All that can be done is to illustrate the funda¬ 
mental principles involved, and these, as here stated, 
taken in connection with the effect re-melting of iron 
has in increasing or decreasing the chemical properties 
of a mixture, as outlined in Chapter XLV., page 302, 
will permit any founder making a study of this chapter 
to intelligently formulate a mixture which will work 
well for any thickness of castings to be used for elec¬ 
trical purposes. 


CHAPTER XLII. 


MIXTURES FOR WHITE IRON CASTINGS 
AND EFFECTS OF ANNEALING THEM. 

There are castings, such as are used for base plates 
in crushers, dies, etc., that are best made of all white 
iron. In making mixtures for such work the thickness 
of the casting as well as the character of the 
iron should be considered, as if this is not done 
castings that were desired to be white can be so 
thick as to cause the resulting iron to be mottled or 
gray. It must also be remembered that there is a 
difference in the strength of white irons, and that such 
castings can be made from burnt or oxidized iron, 
which will be weaker than those made of regular clean 
or unburned iron. Then again, charcoal iron can give 
stronger white iron than coke or anthracite iron. To 
give an approximate idea of the silicon in white iron 
mixtures, for making white castings, the following 
Table 59 is presented. The sulphur is supposed to be 
held at .10 to .15, manganese .50 to .75, and phos¬ 
phorus .25 to .50. If sulphur or manganese are higher 
than shown, then the silicon could be increased, or 
vice versa. The following analysis is supposed to be 
that existing in the castings, and would mean that the 
silicon should be .10 to .20 per cent, higher and the 
sulphur two to three points lower in the iron charged 
for making the casting: 


288 


METALLURGY OF CAST IRON. 


TABLE 59. 


Thickness ) 
of casting. / 


i" 

1 y 2 " 

2" 

2^" 

3" 

2>W 

4 " 

Percentage I 
of silicon, j 

.90 

.70 

.60 

•50 

.40 

•30 

•25 

.20 


In melting white iron mixtures the iron should be 
brought down ‘ ‘ hot, ’ ’ and care taken not to let it get 
too near the danger point of becoming sluggish before 
pouring. White iron, being low in silicon, or high 
in sulphur, will cool very rapidly when it reaches a 
temperature where the eye can detect it commencing 
to lose fluidity. As a general thing the gates for pour¬ 
ing white iron castings should be made from one-third 
to one-half larger than for gray iron, in order that the 
iron may fill the mould rapidly. If castings over 2 
inches thick are desired to be solid on their interior, 
feeding will be found necessary and much care and 
skill are required in the feeding, as white iron has great 
shrinkage and contraction. These two factors are 
about as great again as in gray iron. A contraction 
of about % inch per foot is generally allowed for 
white iron in castings y -inch thick. As they increase 
in thickness the less of course the contraction. 

White iron can be made gray and malleable by 
annealing; in fact, malleable castings are white iron 
annealed. The principle involved consists in packing 
the white iron castings in cast or wrought pots or 
boxes surrounded with iron oxides, generally in the 
form of rolling mill scale and wrought or steel turn¬ 
ings, the whole sometimes treated with a solution of 
sal ammoniac. Then again, hematite ores are used. 
In the selection of such iron oxides care is taken to 
have them as free of sulphur as possible, especially for 






















MIXTURES FOR WHITE IRON CASTINGS, ETC. 289 

small castings. The oxide withdraws carbon and what 
remains exists mainly as temper carbon, a form simi¬ 
lar to graphite but not crystallized. The decarboniz¬ 
ing of castings is greatest near the surface. The 
interior of thick castings often gives up little if any 
carbon. This causes thin castings to appear much 
more malleable, or ductile, than thick ones. The 
reason of this will be better understood when it is 
stated, as shown by Dr. R. Moldenke, that in analyz¬ 
ing a £4-inch malleable casting with the ends broken 
off, which was placed in the shaper and i-i 6-inch cuts 
taken off, the first cut analyzed .16 total carbon, the 
second .65, the third 1.84, the next 3.97, and the last 
4.05 per cent. The original casting contained 4.08 per 
cent, of total carbon, thus showing that the interior of 
thick malleables may be but little changed. This has 
caused an impression that J4 of an inch was as thick 
as was practicable for good malleables. The process 
of annealing, lengthens castings to such an extent as to 
expand them about ^ of an inch per foot. The lighter 
the casting, the relatively greater the expansion. 
This expansion greatly counteracts the excessive con¬ 
traction which must be allowed in making patterns, 
and is such as to usually call for no greater contraction 
than in making patterns for gray iron castings 

The percentage of silicon used for malleables to get 
white iron in castings ranges from .60 to 1.25, running 
lower with the thickness. The iron for making mal¬ 
leables is melted in the cupola, air, and open-hearth 
furnaces. The cupola is generally used for light cast¬ 
ings as it gives a better opportunity to obtain very- 
fluid iron, which will permit its being carried in small 
ladles to the moulds, than that coming from furnaces 


29° 


METALLURGY OF CAST IRON. 


which are generally used for large castings which 
permit of refining, testing, and changing the character 
of the mixture somewhat before the metal is tapped 
into ladles. The Siemens-Martin acid open-hearth 
furnace is now being very successfully employed for 
heavy castings. These furnaces are much hotter than 
air furnaces. The temperature of metal in th.em rises, 
possibly, to 3,500 to 4,000 degrees F. This permits 
the practice of using much steel scrap in with the low 
silicon iron to lower the total carbon slightly, which is 
a desirable point in making malleables as it gives a 
metal, after annealing, softer and tougher on account 
of the lower total carbon than is practicable with air 
furnace or cupola irons. Small quantities of iron ore 
have been added by some thinking to assist in 
reducing the carbon but such is no longer practiced. 
One disadvantage of furnaces over cupolas lies in the 
loss of iron, as the former often causes a loss of 12 per 
cent, of the iron charged by reason of scintillation and 
oxidation of the metal’s surface when exposed to the 
flame. 

The process of annealing is one that varies greatly 
with different firms. One firm may anneal similar 
thicknesses of castings in half the time another will 
take. The changes effected by annealing are chiefly 
in lowering the total carbon in the skin and turning 
the combined that remains into temper carbon, the 
silicon, sulphur, manganese, and phosphorus remain¬ 
ing practically the same. The time occupied in 
annealing ranges from one to seven days, with cast¬ 
ings packed in boxes, etc. This wide difference is due 
to different customs and the character of castings to 
be treated. The ovens used are of simple construction 


MIXTURES FOR WHITE IRON CASTINGS, ETC. 29I 

and generally of rectangular form, being in size about 
eight feet high in the center of the arch, by ten feet 
wide and eighteen feet long. The castings are placed 
in rectangular pots, which are set upon the bottom 
and often built four or five high until a furnace is 
filled. The ovens are heated with natural and pro¬ 
ducer gas; also coke and coal. The action is purely 
one of heating, and the temperature ranges from 1,400 
to 1,900 degrees F. 

Some firms anneal castings without packing them, 

placing them in the ovens singly and allowing the heat 
to come in direct contact with their surfaces. This is 
generally done only with work that is not particular, 
as the heat scales the castings badly. Malleable people 
in general, when an order is very urgent, will often 
anneal castings outright in the melting furnace. The 
results, however, are very unreliable and cause the 
surface to look badly. The effect is generally an 
incomplete conversion of the combined carbon to the 
temper carbon. Annealing is like other workings in 
iron, there are many little things that must be learned 
by experience before success can be had. 


MIXTURES FOR ACID PROOF CASTINGS. 


Mr. Carl Rott, writing in the “ Eisenzeitung” says that the lower thesulphur 
and phosphorus, also the more the carbon is combined to make white iron the 
better for castings that are exposed to acids. Mineral and vegetable acids 
affect irons readily which have high sulphur and graphite contents. Silicon 
and Manganese do not seem to be affected as much. Where the castings are 
not to be machined, the fracture may be mottled to nearly white; where 
machining is done the grain should be as close and fine as possible. The 
author would add that very high Silicon would achieve the latter, but such 
would make very brittle casting. 



CHAPTER XLIII. 


CHEMICAL FORMULA FOR MIXING AND 
MELTING SCRAP IRON. 

Scrap iron, as a general thing, is a product which 
has been re-melted one or more times, and hence must 
fairly show its true grade in a clean fracture. The ad¬ 
vent of chemistry in founding will naturally cause 
some to ask: is it not necessary to know the metalloids 
in scrap iron as well as in pig metal in order to obtain 
desired results from mixtures? It is, of course, well 
to have analyses of scrap the same as with pig metal, 
whenever this is practical, but owing to the fact that 
scrap generally comes to the founder in a promiscuous 
manner, often a little of everything, working by analy¬ 
sis becomes largely impractical, either as to obtain¬ 
ing actual analyses or attempting to guess the chemic¬ 
al properties. In reality, it is not practical to define 
any of the metalloids in scrap iron by guesswork. 
About the only practical plan which the author can 
suggest is to consider and class scrap in the order of 
“grades,” by numbers: as, for example, build an im¬ 
aginary base to define “ grades ” from the texture and 
grain which would be obtained by the remelting of pig 
metal, say, containing i.oo, 2.00, and 3.00 per cent, of 
silicon, respectively, with sulphur supposed to be con¬ 
stant at .030 and phosphorus and manganese as gen- 


MIXING AND MELTING SCRAP IRON. 


2 93 


erally found in their foundry iron, in all the three 
mixtures. By such a method any founder having 
had experience in following chemistry to any degree 
will soon know what “ grade ” the above mixtures of 
pig metal would give were they poured into castings 
ranging from stove plate up to bodies six inches thick, 
and then, when sorting scrap in “ grades,” they would 
simply be contrasted with the ‘ ‘ grade ’ ’ produced by the 
imaginary pig mixture which had been taken to define a 
base for a grade desired. By following such a method 
as this, it is very evident that the grading of scrap 
iron could be reduced to a very satisfactory system, in 
all work where it is economical to utilize scrap iron. 

As a general thing, founders are desirous of utilizing 
all the outside scrap possible in mixture with pig 
metal, because it can generally be bought for less 
than pig iron. With work that permits a good leeway in 
the grade or mixture obtained, such as floor plates, 
furnace castings and heavy machinery not requiring 
much finishing, etc., scrap iron can often compose the 
greater part of the mixture, especially so if silicon pig 
has been used to soften the scrap. In the case of 
stove plate or light machinery castings requiring much 
finishing, much more care is necessary in attempting 
to use much outside scrap iron. The same is to be 
said of chilled work where definite results are to be in¬ 
sured. In many chill work specialties it is often very 
poor economy to adopt the practice of utilizing any 
outside scrap; but, of course, shop scrap, such as 
gates, etc., every shop must work up in mixture with 
its pig metal. An all-pig mixture, of which a correct 
analysis has been given, enables the founder to be 
much more positive in obtaining desired results than 


294 METALLURGY OF CAST IRON. 

where he attempts such results by mixing promiscu¬ 
ous scrap with the pig metal. The loss of a few cast¬ 
ings ofttimes more than counterbalances the differ¬ 
ence in the price of pig and scrap metal, and in some 
cases, if the question of gross tons in pig metal is con¬ 
sidered, the difference will be found strongly in favor 
of the straight pig mixture, as against that of a com¬ 
bination of scrap, which is generally sold by net tons. 

In grading scrap that shows evidence of having been 
chilled, such as that in car wheels, rolls, dies, crushers, 
plows, etc., it is as essential to consider the texture of 
the grey body of the casting or scrap as it is that of 
the depth of the chill, for the reason that the depth of 
the chill part can be deceptive in denoting the true 
grade of the iron, from the fact that degrees in the 
pouring temperature of metal, as well as the thickness 
cf the chill to the limit used for forming the chill part 
of the casting, has an effect in forming the depth of the 
chill, factors more clearly defined in Chapters XLI. 
and LVI.* 

About the worst class of scrap to pass judgment 
upon, in an effort to grade it, is that coming under the 
head of “ white iron.” Where bodies of scrap are all 
white, the silicon contents may, in castings say from 
“ stove plate ” up to two inches thick, contain silicon 
all the way from .50 up to 1.50, and in more massive 
castings than three inches thick, it is generally safe to 
conclude that the silicon can range from .10 up to 0.40, 
with sulphur in any of these thicknesses ranging all 
the way from .050 up to .200. As a basis to guide the 
founder in an effort to grade such irons for mixture 
with softer metals, it can be taken for granted that 
the sulphur is generally very high and the silicon low 

* For a discovery showing that chilled parts give a softer re-melt 
than gray parts of the same casting, see pages 338 and 339. 



MIXING AND MELTING SCRAP IRON. 


2 95 


in all white scrap iron as it comes to the foundry. 

Burnt iron can be said to be the most undesirable 
class of scrap for a founder to handle, and there is a 
doubt in the author’s mind that it pays any founder in 
the end to experiment with it, for making anything 
other than castings like sash weights, for, as a general 
thing, its loss in weight by re-melting will range all the 
way from 30 to 95 per cent. It is a very indefinite 
quality to judge of as to its chemical composition. 
It is safe to say it will greatly injure other irons when 
mixed with them in raising the sulphur and lowering 
the silicon so as to produce a “ white iron,” and can 
often spoil many castings. 

Any intelligent foundry laborer should, with a little 
training, be able to select and pile scrap according to 
its grade. As some would prefer an approximation for 
the silicon and sulphur contents of grey scrap, the au¬ 
thor would say that iron ranging from stove plate up 
to one inch in thickness may be considered as an ap¬ 
proximate equivalent to remelted pig metal that has 
its silicon ranging from 1.50 up to 2.00 per cent., and 
for bodies above one inch thick up to three inches 
thick from 1.00 up to 1.75 in silicon, sulphur in all 
cases to be considered as constant at about .07, Above 
three inches in thickness a grey open fracture can range 
in silicon all the way from. 75 up to 2.50, and the grading 
of such heavy bodies generally requires a more skilled 
eye than with scrap, which might be under three inch¬ 
es in thickness; but practice would soon bring one 
to an approximately close guessing of the grade of 
heavy, as well as light bodies. Where scrap comes 
to the foundry yard in the form of complete castings, 
which the founder will have to break, he can, by “ siz- 


296 


METALLURGY OF CAST IRON. 


ing up * ’ the general proportion and shape of the whole 
casting, judge more readily of the “grade” in the 
massive parts than if it came to his yard in a hap¬ 
hazard form. 

We are compelled to analyze pig metal (as shown on 
page 178) simply because it is deceptive in showing its 
true ‘ ‘ grade ’ ’ to the certainty that scrap iron will 
permit, on account of its being a re-melted product. 
If one wishes to grade scrap by the plan suggested on 
pages 292 to 294, in this chapter, it is best to follow 
a silicon formula for a base, owing to the fact that 
silicon is the element generally largest in gray castings 
excepting carbon and affords a larger range or margin 
in guessing percentages, which if not close to the 
actual silicon contents cannot so greatly result in injury 
as it could if one used a guess of the sulphur for a 
base, and should err much. As scrap with many 
founders constitutes a third and often two-thirds of 
their total mixture, this chapter cannot but be of 
benefit to any who may be desirous of conducting 
their mixtures of scrap iron with the best assurance of 
obtaining desired results without resorting to analysis. 

Much oxide of iron, or rust on scrap iron, is very 
injurious in lowering the silicon of a mixture and thus 
cause a hard iron where a soft one was expected. 
Burnt annealing boxes, old grate bars, etc., give off a 
great deal of oxide of iron. The good iron melts more 
readily than the oxide of iron. If any of the latter is 
not reduced to iron and is carried with the molten 
metal into castings, as it may be, blow holes may be 
formed which are generally to be found in the top sur¬ 
face of castings as they are poured. Where there is any 
apprehension of such difficulty, it is often well to add 


MIXING AND MELTING SCRAP IRON. 


2 97 


a little ferro-manganese to the molten metal. This 
will greatly combine with the oxide and come to the 
surface as slag, which can be skimmed off. Oxide of 
iron combines readily with silica, and for this reason 
when there is any rust on scrap, or old iron, it is often 
desirable to have some sand (which is silica) on pig 
iron, that it may be charged with the scrap iron to assist 
in forming a slag to be carried off by fluxing. This 
will greatly absorb the oxide and give a cleaner iron 
for pouring castings. 

The oxide of iron caused by the oxidation created by 

the blast, in the case of strictly clean iron, may at times 
be insufficient for the amount of sand on pig iron, etc., 
to form the right combination for making a good 
fusible, or thin slag, to carry off the ash of the fuel 
and other dirt out of the cupola. In such cases an 
addition of rusty scrap, etc., may sometimes work 
well. However, it would be better to add limestone 
or other flux to make a fusible slag than to increase 
the oxide of iron or rust, etc., in a cupola. In cases 
of excessive oxide of iron being present, it is abso¬ 
lutely necessary to use limestone or other flux in 
order to make a good slag. It is claimed that high 
cupolas may have a reducing action on oxide of iron, 
so as to obtain more metal from rusty scrap, etc., than 
low cupolas. High cupolas should at least cause a 
greater loosening than low cupolas of the scale from 
iron, and often permit more of it being blown out of 
the stack to remove some of its evils. However, in 
striving to obtain very soft or clean castings, rusty or 
burnt scrap of all kinds is best avoided where practi¬ 
cal. 


CHAPTER XLIV. 


CHEMICAL CONSTRUCTION 
AND STRENGTH OF TYPICAL FOUNDRY 

IRON MIXTURES. 

The chemical construction and highest strength of 

all the prominent mixtures now being used in general 
founding, as obtained by the author for this work to il¬ 
lustrate in a concise and accurate manner true analyses 
of mixtures actually used by our leading founders, are 
shown in Tables 60 and 61. The specimens analyzed 
are taken from the respective tests described in Chapter 
LX. The determinations were made by the able and 
careful chemist, Mr. W. A. Barrows, Jr., of Sharps- 
ville, Pa.: 

Analyses Nos. i and 2 are obtained from “ air fur¬ 
nace ” iron and those of Nos. 3, 4, 5, 6 and 7 from 
cupola iron. A peculiarity which will attract the at¬ 
tention of those making a study of the following Table 
is that of the combined carbon being so high, with low 
sulphur and the silicon not far from 1.00 per cent, in 
analyses Nos. 1 and 2. This illustrates the benefit derived 
from melting iron in an “ air furnace, ’ ’ where it is not 
brought in contact with the fuel to so radically change 
the character of iron, and clearly demonstrates the 
superiority of the “ air furnace ” over the cupola to re¬ 
fine or obtain the best strength possible in cast iron. 


ANALYSES AND STRENGTH OF TYPICAL IkONS. 299 

The author has not seen any analysis of cupola iron 
showing the combination of high combined carbon and 
silicon with the low sulphur shown in analyses Nos. i 
and 2. If any can closely duplicate such a combination 
of metalloids by cupola iron they should obtain about 
the same results in strength derived from the air fur¬ 
nace meltings. This may be closely approximated, 
but the uncertainty of cupola workings, on account of 
the iron being in contact with fuel and blast, makes it 
a difficult and a very unreliable method to adopt. 

The state of the combined and graphitic carbon is 
the final resultant of the combined effects of all the 
other metalloids and chiefly defines what character the 
physical qualities will assume, as regards the strength, 
deflection, contraction, and chill of an iron, f 

TABLE 60. —CHEMICAL ANALYSES OF SPECIALTY MIXTURES IN 

CAST IRON.* 

Arranged according to degrees in strength. 


No. of 
Analysis. 

Specialty 

Mixture. 

Sil. 

Sulp. 

Phos. 

Mang. 

Graph. 

Carbon 

Comb. 

Carbon 

Total 

Carbon 

1 

Gun 

Metal. 

1.19 

•055 

00 

O 

.420 

2.0^0 

1.130 

CD 

00 

0 

2 

Chill 

Roll. 

•7i 

•058 

•543 

.390 

1.620 

1.380 

3.000 

3 

Car 

Wheel. 

.86 

. 1 27 

•348 

.490 

2 550 

.920 

3 470 

4 

Heavy 

Machinery 

1.05 

.110 

•543 

•350 

2.650 

•330 

2.980 

5 

Light 

Machinery 

i.83 

.078 

•504 

.310 

2 500 

■43° 

2930 

6 

Stove 

Plate. 

2-59 

.072 

.622 

•370 

2.950 

•350 

3-3°° 

7 

Sash 

Weight. 

.18 

.138 

.094 

•350 

.150 

2.940 

3.090 


*Nos. 1 and 2 are charcoal irons. 


t The rate of cooling is also to be considered in connection with 
the effects of the metalloids. 


















































































3 °° 


METALLURGY OF CAST IRON. 


Iron of the analysis shown in gun metal can, in 
castings three inches thick and over, be readily ma¬ 
chined and with greater ease than that composing the 
chill roll mixture. Next in hardness to the roll iron is 
the car wheel metal, the other specialties following in 
degrees of softness in the order shown, until sash 
weight iron is reached, which specialty excels all 
shown for being a hard metal as such is strictly a 
“ white iron.” The following Table is a summary of 
the best strength obtained from a series of about ioo 
tests taken with bars one and one-eighth inches in 
diameter, twelve inches between supports, in obtaining 
the transverse strength, more fully described in Chap¬ 
ter LX. A column is also given showing the tensile 
strength of all these specialties. 


TABLE 6l.—SUMMARY OF TYPICAL AMERICAN FOUNDRY IRON TESTS. 
Taken with one square inch area test bars. 


Specialties of Mixtures. 

Transverse 
strength per 
square inch. 

Tensile 
strength per 
square inch. 

Gun Metal. 

3.686 

37 , 110 

Chill Roll. 

3,°44 

30,661 

Car Wheel. . 

2,819 

25,782 

Heavy Machinery. 

2 , 79 1 

25,799 

Light Machinery. 

2,115 

20,655 

Stove Plate. 

1.813 

12,582 

Sash Weight. 

1,480 

7,044 


The Table 61 is no discredit to American foundry- 
men. It displays to the world typical irons challeng¬ 
ing competition in excellence for the various special¬ 
ties shown. 

Ductile cast iron is the term applied to a product 
that was manufactured by the East Chicago Foundry 
Co., for which a tensile strength of 50,000 to 60,000 
pounds per square inch is claimed. The author has 

















ANALYSES AND STRENGTH OF TYPICAL IRONS. 301 


endeavored to obtain all particulars connected with its 
manufacture, but found the process one of which the 
manufacturers did not care to impart any knowledge. 
This was in 1897, but at this time—1902—as far as can 
be learned, the manufacture of this metal has ceased. 

To obtain a knowledge of the strength of other metals 
in comparison to cast iron, see Table 137, page 594. 


1 




CHAPTER XLV. 


EFFECT OF FUEL, FLUXES, TEMPERA¬ 
TURE AND HUMIDITY OF BLAST 
IN RE-MELTING CAST IRON. 

It is as important to possess knowledge of changes 
caused by re-melting iron as it is to know the chemical 
constituents of the iron before it is charged into the 
cupola. For the past seven years the author has fol¬ 
lowed closely the records which were daily compiled 
at our foundry of the chemical properties in the iron 
charged and also the product received from the cupola 
in “ heats ” ranging from 40 to 100 tons. The follow¬ 
ing Table, No. 62, compiled from one week’s melting 
in this foundry, with coke .80 to 1.00 in sulphur, will 
serve to illustrate the change due to silicon and sulphur 
in re-melting iron: 

TABLE 62. — DECREASE IN SILICON, AND INCREASE IN SULPHUR, BY 

RE-MELTING IRON. 


Silicon 
in pig. 

Sulphur 
in pig 

Silicon 
in castings. 

Sulphur 
in castings. 

Loss in 
silicon. 

Gain in 
sulphur. 

1 93 

.022 

1 77 

.040 

.16 

.018. 

1 84 

.016 

1 65 

.046 

.19 

.030 

1.78 

.031 

1 58 

.056 

.20 

.025 

1-52 

.029 

1 39 

.061 

•13 

.032 

1.46 

.027 

1-33 

.056 

•13 

.029 

1.28 

.021 

1.10 

.067 

.18 

.046 


The increase in sulphur in re-melting is dependent 

















EFFECT OF FUEL, FLUXES, TEMPERATURE, ETC. 303 

upon the amount of sulphur in the fuel, the silicon 
and manganese in the iron, the flux and the heat in 
the cupola. An increase of the sulphur in the fuel or 
flux will cause a corresponding increase of sulphur in 
the iron; while the less fuel used and the better a 
cupola is fluxed or ‘ ‘ hot iron ’ ’ produced, the less sul¬ 
phur will the re-melted iron contain. 

The decrease or oxidation of silicon is greater the 
higher the blast pressure and also the hotter the iron 
is melted. In a general way, it can be said that sili¬ 
con is decreased from one to three-tenths of one per 
cent, and sulphur increased from one to six hun¬ 
dredths of one per cent., where the fuel holds .80 to 
1.00 in sulphur. The author has, in a few rare cases, 
found the silicon to be but very little decreased, but 
never found a re-melt where the sulphur was not 
materially increased. The increase of one point of 
sulphur can often neutralize the effect of ten to fifteen 
points of silicon, and hence, owing to the increase of 
sulphur being so powerful in neutralizing the effects 
of silicon, it is very essential that all conditions influ¬ 
encing the increase of sulphur should be guarded and 
controlled so far as practical, in order to be best as¬ 
sured of obtaining any desired results in the castings. 

The changes due to manganese in re-melting iron 
are toward its reduction. The hotter the metal, the 
higher the blast, the greater its reduction. The 
reduction can range from 10 to 30 points. The more 
manganese iron contains, the less the increase of 
sulphur, owing to the affinity manganese possesses for 
carrying off sulphur in the slag. 

Phosphorus may be called a “ sticker, ” as when 
once absorbed by iron it cannot be easily eliminated. 


3°4 


METALLURGY OF CAST IRON. 


In re-melting iron, whatever phosphorus the fuel oi 
flux may contain will largely go to the iron, and hence 
phosphorus has a tendency to be increased every time 
iron is re-melted. Its influence in effecting changes in 
the other elements is to favor the reduction of silicon, 
sulphur and manganese, owing to the quality of phos¬ 
phorus which causes iron to have greater fluidity and life. 

Total carbon is, as a general thing, increased by 
re-melting. The amount is chiefly dependent upon the 
percentage of fuel used, and the length of time the iron 
is in the cupola. Little fuel and quick melting may 
at times cause a slight reduction of the carbon. In 
the case of excessive fuel which can give hot iron and 
cause slow melting carbon may be increased. It is 
also, to some degree, dependent upon the silicon and 
manganese present. The former retards, while the 
latter promotes the increase of carbon. 

Combined carbon with the silicon above four per 
cent., and sulphur not over .01, may sometimes be 
slightly reduced. After silicon has decreased to 
4.00 with the sulphur above .02, every re-melt will 
surely increase the combined carbon until the silicon 
is so decreased and the sulphur increased that “ white 
iron” will be produced, giving an iron which may have 
its carbon almost wholly in a combined form. 

Graphitic carbon is increased accordingly as combined 
carbon is decreased, and the elements best calculated 
to promote its formation are silicon about 3.50 and 
phosphorus not above 1.25, with low sulphur. 

In a general way it can be said that with iron 
melted in the cupola, the silicon, manganese and 
graphitic carbon are decreased, while the sulphur, 
phosphorus and combined carbon are increased. 


EFFECT OF FUEL, FLUXES, TEMPERATURE, ETC. 305 

In connection with a study of this chapter, readers 
are referred to tests showing losses of silicon and man¬ 
ganese, and gains in sulphur, phosphorus, and carbon 
found in Tables 73 and 76, pages 334 and 341. It is to be 
understood that the foregoing pages of this chapter deal 
with cupola practice only; and as the author has had 
no opportunity of late for experimenting with results 
to be derived from re-melting iron in an “ air furnace, ’ 
he cites the following extract from Sir William Fair- 
bairn’s report before the British Association of Science 
on the effect of re-melting iron in an “ air furnace ” 
eighteen times, in which he describes the action of re¬ 
melting as follows: 

Phosphorus increased from 0.47 to 0.61. This was probably 
due to loss of metal by oxidation. Manganese decreased from 
1.75 to .12. This would tend to improve the metal during the 
earlier meltings. Silicon was reduced from 4.22 to 1.88. The 
first effect of this reduction was to produce softer metal and 
lower combined carbon, since silicon was present in quantity in ex¬ 
cess of that necessary for the softest metal. On further reduction 
of silicon the metal became stronger and harder. But in these ex¬ 
periments the reduction was not carried sufficiently far to cause 
any deterioration due to sufficiency of silicon. Sulphur in¬ 
creased from .03 to .20, and this is one of the most important 
changes which took place, the increase in sulphur tending in the 
same direction as the loss of silicon, viz., the production of high 
combined carbon. The combined carbon increased considerably 
after the eighth melting, ultimately reaching to over two per cent. 

By Fairbairn’s experiments we find that the results 
of re-melting in an air furnace are in part similar to 
those of a cupola, and in both cases it is a subject as 
necessary to be understood, in order to obtain desired 
ends, as is that of knowing the chemical properties of 
the iron before it is charged. 

There have been experiments conducted in order to 


306 metallurgy of cast iron. 

observe whether there would be any difference in the 
strength of iron taken from the beginning, middle, 
and end of ‘ ‘ heats, ’ ’ where a uniform mixture was 
used throughout a heat. Results received affirm that 
some would obtain the strongest test at one part, 
while others would receive them from another part of 
a heat. In this practice the author cannot conceive 
of any uniformity being obtained unless the manage¬ 
ment is such as to insure a like temperature and flux¬ 
ing at every part of a “ heat,” and in this quality gen¬ 
erally lies the secret of the difference between one 
founder and another. One may have a cupola giving 
the hottest iron at the beginning of a heat while 
another will obtain this at the middle or the end. 
According to the variation of temperature when re¬ 
melting iron, so is the combined carbon affected by 
changes in the silicon, sulphur and manganese; and 
taking this view of the subject the author believes that 
all can understand why we find founders disagreeing 
in such tests. 

As the humidity of the air can, to some extent, pro¬ 
duce changes in the smelting or melting of iron, one 

* 

heat from another, the author appends the following 
excellent article written by Mr. A. Sorge, Jr., M. E., 
in the Foundry, April, 1896: 

That variations in the humidity of the atmosphere and its tem¬ 
perature do affect the operation of melting iron in a cupola, will 
be conceded by foundrymen who have observed the difference in 
melted iron on different days. Iron is liable to be cold and slug¬ 
gish with the same charges of fuel on cold and moist days, while 
it is hot and fluid on warm and bright days. 

It is therefore reasonable to look for one cause of poor melting 
to the atmospheric conditions. Let us assume that we are melt¬ 
ing at a ratio of eight iron to one coke on an ordinary bright day, 


EFFECT OF FUEL, FLUXES, TEMPERATURE, ETC. 307 

when the temperature is 62 degrees F., and the percentage of 
moisture in the atmosphere about 0.52 per cent., which is about 
the average in Chicago. 

It has been found by experience that about 33,000 cubic feet of 
air are required to melt 2,000 pounds of iron in ordinary cupola 
practice. This air will weigh about 2,500 pounds, and is heated 
originally to a high temperature by the ignited coke before it be¬ 
comes active in supporting further combustion. Also any mois¬ 
ture contained in this air must be brought to the temperature of 
the gases which escape from the top of the cupola. This latter 
temperature varies greatly, but will be in the vicinity of 500 de¬ 
grees F. for good practice. 

If the temperature of the atmosphere should drop to 32 de¬ 
grees F., this means that the air delivered to the cupola must be 
heated 30 degrees, so as to bring it to the normal. The specific 
heat of air being taken at 0.238, we obtain 2,500 X 30 X 0.238 = 
17,850 B. T. U. as the amount of heat required to do this work, 
or theoretically about 1^ pounds coke would be consumed if we 
obtained perfect combustion. The fact being that the actual 
amount of heat obtained from the combustion of coke in a cupola 
is only about % of the theoretical, it follows that the actual coke 
consumed for this extra heating is about 5 y 2 pounds, which should 
be added to the usual amount of 250 pounds per ton of iron, mak¬ 
ing 255^ pounds, or a ratio of about 7.8 iron to 1 coke. 

If, at the same time, the air is charged with particles of mois¬ 
ture, as when a heavy snow-storm is in progress, it will contain, 
say, about 4-10 per cent, of frozen water. In the 2,500 pounds 
total this will amount to 10 pounds, which must be transformed 
into vapor at 500 degrees F., involving 14,740 B. T. U. of heat. 
On the other hand, this amount is reduced by the heat expended 
in raising the average vapor of 0.52 per cent, in 62 degrees air to 
500 degrees F., which amounts to 2,714 B. T. U., leaving an extra 
amount of 12,036 B. T. U. consumed by the snow, which will 
again require about 3.6 pounds coke. 

The total coke consumption in the above case will therefore be 
259.1 pounds per ton of iron, or a ratio of 7.7 iron to 1 coke, in 
order to deliver the melted iron in the same condition as on an 
ordinary day. In other words, an additional fuel consumption 
of a little over 3.6 per cent, is needed under the above conditions, 


3°8 


METALLURGY OF CAST IRON. 


so as to obtain the iron in the same state of heat and fluidity as 
when ordinary dry air at 62 degrees is used. 

On the other hand, a higher temperature and greater dryness 
of the atmosphere will operate in permitting the amount of fuel 
to be reduced. 

In the above figures I have assumed ordinary conditions, but 
the actual practice must be carefully taken into consideration 
wherever it is desired to figure out the effects in any particular 
case, and it is well worth a foundry man’s time to go into this 
question, figuring out the extra amounts of coke needed under 
various conditions of moisture and temperature, when a short 
observation of an ordinary hygrometer and thermometer will 
enable him to avoid the risk of cold and sluggish metal on any 
day. 

Mr. W. H. Fryer has shown and published the 
statement* that air containing 0.8 per cent, of mois¬ 
ture will introduce about 89.6 pounds of water into a 
blast furnace per ton of iron made, using about 2,250 
tons of coke for fuel. This is a factor the founder 
should not lose sight of. When air is moist, it is to 
some degree practically the same thing as fuel being 
water-logged. With very wet fuel, as many founders 
know, a larger percentage is necessary to re-melt iron 
than if the fuel were perfectly dry, and also that this 
can cause trouble much more readily in the line of 
“ bunging up ” a cupola. For further information of 
the effects of humidity, see Chapters IX. and X. 


* Journal of the Iron and Steel Institute, Vol. II., 1887. 



CHAPTER XLVI. 


LOSS OF IRON BY OXIDATION IN 

CUPOLAS.* 

The amount of iron lost by melting is as important 
an item for consideration as that of any other material 
necessarily destroyed in the making of castings. 
Many founders endeavor to keep a close record of such 
losses, but there are many who cannot. Founders 
who can clean up each day’s heat of castings and 
collect all their fine shot, scrap, and gates the day 
following each heat are in the best position to obtain 
the greatest accuracy in such records, but shops where 
castings lie in the sand from one to six days,or more 
before they can be removed or cleaned up find the task 
a much more difficult one. In buying pig iron the 
furnaceman allows 268 pounds per ton for scale and 
sand on sand cast pig,and 240 pounds on chilled cast pig. 
How much of this is actual refuse is difficult to deter¬ 
mine accurately. When first studying the method of 
casting pig metal in chills, the author could see 
nothing unfavorable to the universal adoption of metal 
so cast for founders and steel makers. It was not until 
at a meeting of the Pittsburg Foundrymen’s Associa¬ 
tion, December 3, 1898, where a member made the 
claim that a greater loss would be incurred by the use 
of chilled cast pig iron, in re-melting iron, than by 
having sand and scale on it — which was said to afford 

*This chapter is a revised extract of a paper presented by the 
author to the Pittsburg Foundrymen's Association, January, 1898. 



3 TO 


METALLURGY OF CAST IRON. 


a protection to the iron against oxidation, or being 
burned away while being brought to a liquid state — 
that any disadvantage was apprehended. The author 
has no knowledge of the process by which the above 
member arrived at his conclusions, and can only 
say that to obtain definite proof of this claim 
steps differing from general practice in melting are 
necessary. The author, realizing this, made a series 
of original tests embodying sixteen heats, made in the 
twin shaft cupola Fig. 56, page 241, and shown in 
Tables 63 to 66. In making the comparative oxidation 
tests shown in these tables much care was necessary in 
preparing the cupola and collecting its refuse. In get¬ 
ting this cupola ready (Fig. 56) for a heat both depart¬ 
ments were picked out and daubed up smoothly and 
then blacked over with graphitic or lead blacking. 
Such a plan insured that no iron stuck to the sides from 
the preceding “heals,” to be melted down with, or 
change the irons obtained from the respective sides. 
The bottom was not dropped after heats, as in ordinary 
practice, but after the cupola had cooled down the 
refuse was picked out from the top downward by hand, 
and every particle carefully pounded in a pan to dis¬ 
cover any fine shot or pieces of scrap that might 
exist in the burnt coke, dross, or slag remaining in the 
cupola at the close of a heat. This was then weighed 
on fine scales. By this plan not a single ounce of metal 
that remained as such could escape being found. 

Heats Nos. 1 and 2, Table 63, were charged with 
rolls that were cast from the same ladle, half being 
made in sand and half in chill molds, such as seen at 
Fig. 59. The roll castings were after the pattern seen 
in Fig. 58, which it may be said was the same form in 


LOSS OF IRON BY OXIDATION IN CUPOLAS. 




which the iron was charged in heats Nos. 3, 4, 5, 6, 7, 
and 8, as well as those shown in Tables 65 and 66, 
where rolls are cited. The loss from heats Nos. 1 and 
2 ran about 5 per cent, for the sand rolls and 3 per 
cent, for the chilled iron. When the first two heats 
are compared with those of the chilled iron by the 


TABLE 63. —COMPARATIVE OXIDATION TESTS OF PROTECTED AND 
UNPROTECTED IRON SURFACES. 



Heat 
No. 1. 

Heat 
No. 2. 

Heat 
No. 3. 

Heat 
No. 4. 

Heat 
No. 5. 

Heat 
No. 6. 

Heat 
No. 7. 

Heat 
No. 8. 

Kind of Metal 
Charged. 

Sand and 

Chill Rolls. 

Sand and 

Chill Rolls. 

Chill Rolls. 

Chill Rolls. 

Chill Rolls. 

Chill Rolls. 

Chill Rolls. 

Chill Rolls. 

Kind of protec¬ 
tion used on 

Sand 

Sand 

Lead 

Lead 

Lime 

Lime 

Sil. 

Sil. 

coated rolls... 

.Scale. 

Seale. 

Wash. 

Wash. 

Wash. 

Wash. 

Soda. 

Soda. 

Weight of un- 









protected and 









protect ed 









charges.. 

114 lbs. 

80 lbs. 

84 lbs. 

54 lbs. 

81 lbs. 

85 lbs. 

78 lbs. 

90 lbs. 

Blast put on. 

3-36 

3-18 

3-47 

2.20 

3 -i 7 

2-54 

3-04 

3-43 

Protected iron 









running. 

3-4454 

3-2754 

3-5354 

2.27 

3-25 

3-°°54 

3-0954 

3-5254 

Unprotec ted 









iron running... 

3-43 

3 - 25 

3-52 54 

2.26 

3-2354 

3.00 

3-09 

3-52 

Protected iron 
all down . 

4 - 03/4 

3-40 

4 - 03 % 

2-3454 

3-3754 

3 -ii 54 

3.20 

4-0754 

Unprotected 


3-3754 







iron all down.. 

4.01 

4.02 

2-3354 

3-37 

3 - 1*54 

3-1954 

4.06 

Weight of pro- 





77 lbs. 

81 lbs. 

75 lbs. 

87 lbs. 

tected iron ob- 

108 lbs. 

75 lbs. 

81 lbs. 

52 lbs. 

tained.. 

30Z. 

2 oz. 

1 oz. 

1 oz. 

13 oz. 

15 oz. 

II oz. 

8 oz. 

Weight of un- 





78 lbs. 

81 lbs. 

75 lbs. 

87 lbs. 

protected iron 

no lbs. 

77 lbs. 

81 lbs. 

52 lbs. 

obtained . 

2 oz. 

2 oz. 

1 oz. 

3 oz. 

30Z. 

14 oz. 

12 oz. 

6 oz. 

Loss of protect- 

5 lbs. 

4 lbs. 

2 lbs. 

1 lb. 

3 lbs. 

3 lbs. 

2 lbs. 

2 lbs. 

ed iron . 

13 oz. 

14 oz. 

15 oz. 

15 oz. 

30Z. 

x oz. 

50Z. 

8 oz. 

Loss of unpro- 

3 lbs. 

2 lbs. 

2 lbs. 

1 lb. 

3 lbs. 

3 lbs. 

2 lbs. 

2 lbs 

tected iron. 

14 oz. 

14 oz. 

15 oz. 

13 oz. 

X oz. 

2 oz. 

4 oz. 

10 oz. 


* This has reference to the sand that formed a scale on the sand cast rolls 
and which were charged on one side, while the chilled rolls were charged on 
the other, of the cupola, for heats Nos. i and 2. For heats Nos. 3 to 8 all chill 
rolls were used for both sides, the only difference being the chills for one side 
were coated as described on pages 313, 314 and 317. 






































































































































3 12 


METALLURGY OF CAST IRON 


TABLE 64. —COMPARATIVE FUSION TESTS BY IMMERSION OF IRONS 
SHOWN IN TABLE 63. SEE PAGE 314. 



Heat 
No. 1. 

Heat 
No. 2. 

Heat 
No. 3. 

Heat 
No. 4. 

Heat 
No. 5. 

Heat 
No. 6. 

Heat 
No. 7. 

Heat 
No. 8. 

Time of im¬ 
mersing rolls 
2%" diameter * 

4:00 

4:00 

4:00 

4:00 

4:00 

4:00 

4:00 

4:00 

Time of total 
fusion of sand 
protected rolls 

4:04% 

4:06 

4:0954 

4:io54 

4:06 

4:0654 

4:04 

4 :o 4 K 

Time of total 
fusion of un¬ 
protected rolls 

4:03 

4=0354 

4:0254 

4*02^ 

4:03 

4:0354 

4:02% 

4:0354 

Difference i n 
time of melt¬ 
ing. 

1 44 ni. 

2 54 m. 

7 m. 

754 m. 

3 m. 

354 m. 

i54 m. 

i54 m. 


'*The time of dipping was changed to the unit of 4:00 o’clock shown so as to 
make the table easier of solution. The relative differences, however, were 
kept exactly the same as originally found. 



FIG. 58. 


FIG. 59. 




















































LOSS OF IRON BY OXIDATION IN CUPOLAS. 


313 


protected and unprotected plan seen in heats Nos. 3 to 
8, it will appear how unreliable are the data as to how 
much sand or scale one is crediting to iron when 
weighing the charges of sand-coated pig irons for 
regular cupola practice. To avoid this uncertainty, I 
adopted the idea of taking gray iron cast in chill 
moulds for both sides of the cupola, coating that for 
one side heavily with some heat resisting material (by 
giving each three coats and drying them in an oven 
after every coating), and charging the other side with 
the surface of the chilled or sandless gray iron exposed. 
By weighing the iron before it was coated I knew 
exactly what weight of iron was going into the respec- 


TABLE 65.—COMPARATIVE OXIDATION TEST OF IRONS CHARGED ON 
HIGH AND LOW BEDS OF FUEL. SEE PAGE 315. 



Heat 
No. 9. 

Heat 
No. 10. 

Heat 
No. 11. 

Heat 
No. 12. 

Kind of metal charged. 

Chill rollsuu- 
protected. 

Chill rollsun- 
protected. 

Chill rolls 
coated with 
lead wash. 

Chill rolls 
coated with 
lead wash. 

Weight of charges each side. 

64 lbs. 

73 lbs. 

75 lbs. 

100 lbs. 

Blast on.. 

3-55 

4.27 

3-42 

3-33 

High bed running. 

4.02 

4-38 

3-50 

3-45 

Low bed running. 

4.00 

4 - 33/4 

3 - 47 % 

3-39 

High bed all down... 

4 -U% 

4.48 

3 -° 3/4 

4 05 

Low bed all down . . 

4.08 

4.44 

4 - 56 ^ 

3-55 

Weight of iron obtained from high bed 

62 lbs. 

6 oz. 

70 lbs. 

7 oz. 

72 lbs. 

9 oz. 

96 lbs. 

12 oz. 

Weight of iron obtained from low bed.. 

62 lbs. 

10 oz. 

00 0 

0 f? 

• N Sf 

72 lbs. 

14 oz. 

96 lbs. 

14 oz. 

Loss of iron from high bed.... 

1 lb. 

10 oz. 

2 lbs. 

9 oz. 

2 lbs. ■ 
7 oz. 

3 lbs. 

4 oz. 

Loss of iron from low bed. 

i lb. 

6 oz. 

2 lbs. 

8 oz. 

2 lbs. 

2 oz. 

3 lbs. 

2 oz. 


tive sides of the cupola. In reality, I consider this the 
only true way of making a comparison between chill 















































































314 METALLURGY OF CAST IRON. 

and sand-cast pig metals to judge whether scale or sand 
prevents a loss of iron by oxidation. For heats Nos. 
3, 4, 5, 6, 7, and 8 all chilled irons were used, the only 
difference being that I used different materials for 
coating or protecting the surface of the chill, or sand¬ 
less pig rolls, which were to be charged as protected 
irons. Of the three coatings used — lead wash wet 
with molasses water, lime wash which was hardened 
with salt, and silicate of soda — the lead wash afforded 
the best protection. This was proven by the less time 
required by unprotected chills to start and end in melt¬ 
ing than the chill or sandless pig rolls having their 
surfaces protected or coated with the lead wash. 

Believing an immersion test would furnish a good 
check on the action of the different protectors — lead, 

TABLE 66 .—COMPARATIVE OXIDATION TEST OF STOVE PLATE AND 

HEAVY IRON. SEE PAGE 3 1 6 . 



Heat 
No. 13. 

Heat 
No. 14. 

Heat 
No. 15. 

Heat 
No. 16. 


£ * 
42 « 

<u 

-W 

c/f 

d> 

cti . 

C/3 

-w 

*2 

Kind of metal charged. 

Stove p 
and roll 

Stove p 1 
and roll 

x 2 

>P a r— 

a 

24 -ineh p 
and roll: 

Weight of charge each side. 

100 lbs. 

65 lbs. 

100 lbs. 

65 lbs. 

Blast on.. 

3-34 

3.06 

2 20 

3 - 11 

Heavy iron running. 

3 - 39/4 

3.12 

2.25 

3-i6 % 

Plate running. 

3 - 35^4 

3-07 

2.2314 

3-15 

Heavy iron all down. 

3-54 

3.21 

2-35 

3-2214 

Plate all down . 

3-44 

3-13 

2-33 

3.21 

Weight of heavy iron obtained. 

96 lbs. 

15 oz. 

62 lbs. 

II oz. 

97 lbs. 

2 oz. 

63 lbs. 

1 oz. 

Weight of plate obtained. 

89 lbs. 

14 oz. 

57 lbs. 

9 oz. 

94 lbs. 

5 oz. 

61 lbs. 

II oz. 

Loss of heavy iron.... 

3 lbs. 

1 oz. 

2 lbs. 

5 oz. 

2 lbs. 

14 oz. 

1 lb. 

15 oz. 

Loss of plate. 

10 lbs. 

2 oz. 

7 lbs. 

7 oz. 

5 lbs. 

II oz. 

3 lbs. 

5 oz. 


















































































LOSS OF IRON BY OXIDATION IN CUPOLAS. 


315 


lime, and silicate of soda, shown in Table 63 — I cast 
and prepared two rolls from each heat, coating one and 
leaving the surface of the other bare, connecting the 
two for immersion in liquid iron by a rod M after the 
plan seen in Fig.. 51, page 232. By a study of 
Table 64, one will perceive that the chilled rolls 
coated with lead best resist fusion by immersion, as 
well as the heat of melting in the cupola. In fact, all 
the immersion tests made coincided very closely with 
the results found by the twin shaft cupola experiments, 
and strongly confirm the conclusion to be drawn from 
Table 63, page 311. 


TABLE 67. —ANALYSES OF SILICON AND MANGANESE IN LOW AND 
HIGH BED IRONS, OF TABLE 65. SEE PAGES 313 AND 317. 



Heat No. io. 

Heat No. n. 

Silicon. 

Man. 

Silicon. 

Man. 

Height of bed, low side. 

1.41 

•34 

1.46 

.38 

Height of bed, high side. 

1.36 

• 3 i 

1.41 

•32 

Difference.. .... 

•05 

•03 

•05 

.06 


After completing the tests illustrated in Tables 63 
and 64, I thought it desirable to learn what difference, 
if any, high and low beds of fuel might cause in losses 
of iron. By referring to Table 65 it will be seen that 
tests Nos. 9 and 10 were heats having the chilled pig 
rolls charged without coating, whereas heats Nos. 11 
and 12 had the surface of the iron protected with a 
wash of lead blacking. In all these four heats, it will 
be seen the loss was slightly greater with the iron 
charged on the high bed, or that side using the most 
fuel. While this is true, it is to be said that more fine 
shot and scrap was found in the side having the low 
























3 l6 


METALLURGY OF CAST IRON. 


bed. In general practice, the chances are that the 
majority of founders would not go to the labor and 
expense of endeavoring to collect all this fine shot and 
scrap so closely as was done with these tests. Hence 
the loss of iron to be experienced in actual practice can 
be reckoned as the greatest with founders aiming to 
economize fuel in an extreme measure, thereby not 
procuring good hot iron. All experienced founders 
know that high beds of fuel give hotter iron, but that 
it melts slower than iron charged on low beds. The 
difference in the heights of bed coke used in the experi¬ 
ments in Table 65 was about 10 inches. 

The four heats seen in Table 65 having been com¬ 
pleted, I next tested stove plate iron in comparison with 
the sandless roll iron as used in previous heats. In 
selecting the stove plate, I secured it as clean as I 

TABLE 68.—ANALYSES OF IRON IN SLAG FROM LOW AND HIGH BEDS, 


STOVE PLATE AND HEAVY IRONS. SEE PAGE 317. 



Per cent of 
iron in slag, 
Heat No. io. 

Kind of iron. 

Per cent of 
iron in slag, 
Heat No. 13. 

Percent of 
iron in slag, 
Heat No. 14. 

Height of bed, low side... 

31-39 

Heavy iron 

25-13 

26.78 

Height of bed, high side. 

24.06 

Stove plate 

23-56 

16.97 

Difference. 

7-33 


i -57 

9.81 


could, picking it out from the scrap pile. Notwith¬ 
standing this, its loss will be seen, by referring to 
Table 66, tests 13 and 14, to exceed by about 7 per cent, 
that of the more solid heavy iron used in comparison 
with it. 

After testing the stove plate referred to, I then ran 
two heats having a plate casting ^ of an inch thick, 





















LOSS OF IRON BY OXIDATION IN CUPOLAS. 317 

broken in pieces about 4 inches square, and melted it in 
comparison with the rolls or heavier iron, as seen in 
tests 15 and 16. This %-inch plate iron was cast espe¬ 
cially for the purpose and used the day following, so 
that it was perfectly free from all rust or dirt scale, its 
coat being only that of the film of oxide formed on its 
surface while in the green sand mould. The loss of 
this 24 -inch plate will be seen to be about 5 per cent., 
and this can be taken as a good test for this character 
of flat-faced surfaces, when charged in the form of 
clean scrap, not exceeding 1 inch in thickness. It 
will be well to state that the iron used for pouring 
the chilled or sandless gray roll bodies used through¬ 
out all the heats herein described (form shown in Fig. 
58) were taken from one of our regular shop cupola 
heats and would average about 1.70 silicon, .045 
sulphur, .50 manganese, and .10 phosphorus. Owing 
to this iron being moderately high in silicon and fairly 
low in sulphur, it would only chill to a depth of about 
24 of an inch in the small rolls shown. Such a depth 
of chill on the surface of the rolls used for the heats 
herein described, would agree fairly well with that 
found in general gray pig irons that had been cast in 
chills instead of sand molds, and I believe all will con¬ 
cede it to be an iron well suited for tests on the com¬ 
parative oxidation of chilled and sand-cast pig metal. 
Table 67 would show that greater silicon and manga¬ 
nese were lost on the high beds than the low beds of 
fuel. Another interesting point, which may surprise 
many, is that the slag which came from the stove plate 
iron, as seen in Table 68, has a less percentage of iron 
in it than that which came from the heavier or sandless 
gray roll iron. While this is shown as such, it does 


3 lS 


METALLURGY OF CAST IRON. 


not imply that there is a less total loss of iron with 
stove plate than heavier iron, as we know by actual 
practice the reverse to be true. The greater loss of 
iron by remelting stove plate than is found in heavier 
irons, is due to the films of oxide, or scales of rust and 
dirt which, when attacked by the high temperatures of 
a cupola, etc., in blast, either go to make extra slag or 
escape out of the stack in other forms. This phenom¬ 
ena in extra slag production is exhibited in actual 
practice whenever we melt dirty or burnt iron, as all 
founders well know. 

The facts presented herewith suggest that opinions 
of the past in regard to oxidation of metal are in many 
cases not well founded, and that where losses of iron 
have been attributed to oxidation of the metallic iron 
proper, or a reduction of the metalloids, proper account 
has not been taken of the dirt, rust, or films of oxide 
that might have covered the surface of the pig or scrap 
iron used. We are led to conclude that if it were pos¬ 
sible for us to secure clean iron, free of all sand, rust 
or scales, or oxide of iron, the loss of metallic iron due 
to oxidation proper is not as large as has been generally 
supposed. 

During the discussion of this paper, Mr. Uehling 

showed the reliability of the author’s experiments on 
oxidation by presenting the following losses (Table 69) 
calculated from the results given in Table 63, page 311; 

TABLE 69. 


Sand iron lost. 

Lime wash loss.. 

Graphite wash loss. 

Chilled iron loss. 

Soda silicate wash loss 


5.595 per cent average. 
.3.765 “ 

3.425 “ 

3-395 “ 

.2.875 “ “ “ 














LOSS OF IRON BY OXIDATION IN CUPOLAS. 3I9 

This table, it was contended, showed the remarkable 
accuracy attained with even such small heats. Mr. 
Uehling in explaining the reason why chilled pig would 
not waste as much as the sand pig, said it was due to 
the fact that a slight formation of oxide of iron in the 
case of the sand pig would immediately cause a slag¬ 
ging action, the iron thus being absolutely lost, whereas 
in a chilled pig the oxide coming in contact with incan¬ 
descent carbon fuel would be reduced back to iron • 
again. Here also, he said, would come the advantage 
of plenty of fuel to keep the flame as constantly up 
to the reducing action as possible. 

LOSS OF IRON BY SLAGGING OUT. 

The following data was first presented by the author 
before the Western Foundrymen’s Association April 
18, 1894. Iron is lost by being carried off with slag as 
well as by oxidation in a cupola. The author was led 
into an investigation of this subject on account of the 
peculiarities in slag foaming which came from three suc¬ 
cessive large heats, and was never known to occur before 
in the cupola used. In analyzing the slag to discover, 
if we could, the cause of the slag foaming, we also 
took note of the iron it contained. The slag coming 
from one of the foaming heats, when analyzed, was 
found to contain an oxide of iron equivalent to 26.80 
per cent, metallic iron. In addition to this there was 
1.97 per cent, of very fine shot iron in the sample of 
slag selected, which was an average of the whole heat. 
This, no doubt, was from droppings of melted iron, 
which elsewhere than at the slag hole would have greatly 
found its way to the bottom and constituted part of the 
liquid metal to be drawn off at each tap. The fine shot 


320 


METALLURGY OF CAST IRON. 


iron I consider is likely to occur in any heat, the 
quantity escaping with the slag being dependent on 
the pressure of the blast and the size of the slag 
hole. 

A short time after the difficulty with foamy slag 

I gave considerable attention to iron in slags, and had 
analyses made by Mr. Mac Shiras, who found the fol¬ 
lowing weights of iron to be lost through slags: In a 
heat of forty tons, March 15, 1894, we had slag coming 
from the slag-hole weighing 1,700 pounds. The 
analysis showed this slag to contain 3.34 per cent, of 
shot iron and oxide of iron equivalent to 17.25 per 
cent, metallic iron, a loss of 350 pounds of iron in the 
1,700 pounds of slag, and to the total weight of iron 
charged the percentage of loss would be thirty-nine 
one-hundredths of one per cent. 

Another heat of forty tons on March 19, 1894, which 
we followed up, showed the slag weighed 1,630 pounds. 
The analysis of this gave 2.70 per cent, shot iron and 
an equivalent of 15.69 per cent, of metallic iron, a loss 
of 300 pounds in 1,630 pounds of slag, and to the total 
weight of iron charged the percentage of loss would 
be thirty-three one-hundredths of one per cent., which, 
figuring the iron at $ 12 per ton, would show a loss of 
$1.58, or a little less than four cents per ton. One 
factor which it will be profitable to dwell upon before 
proceeding further is the reason for the difference of 
loss in the two forty-ton heats. As our metal is car¬ 
ried away from the cupola by a five-ton ladle, and 
there are often lulls in getting back with the crane 
ladle, I permitted the practice of leaving the slag-hole 
open all the time, so as to make sure that the slag or 
metal did not reach the tuyeres. Feeling satisfied we 


LOSS OF IRON BY SLAGGING OUT CUPOLAS. 


321 


were losing some metal by letting the blast continually 
blow out of the slag hole, I decided to try, in the second 
heat quoted, to plug and tap the slag-hole at intervals, 
or just a few minutes before tapping out. By doing 
so we obtained, as shown, a saving of six one-hum 
dredths of one per cent, of the total weight of iron 
charged, or in other words, we saved 29 cents in the 
heat of 40 tons at the risk of letting the iron or slag 
fill up the tuyeres, and hence bung up the cupola. By 
such a method of retarding melting, to save a little iron, 
we might have lost many dollars in castings through 
bad melting or dull iron. 

Where conditions are favorable to tapping a slag- 
hole at intervals, or just before tapping out the iron, 
on account of having a greater distance between the 
tuyeres and slag-hole, then we had, the above figures 
clearly demonstrate the economy of such practice; and 
it is one that as a general thing can be safely followed; 
but in cases where the tapping out and plugging up of 
a slag-hole would require a man solely to look after it, 
nothing is to be saved by this practice. We used all 
pig; no scrap excepting a few “gates,” which, for a 
50-ton heat would weigh about two tons; and Connells- 
ville coke for fuel, of which 2,000 pounds were used for 
the bed and 450 pounds between charges. The pig on 
bed was 8,000 pounds and between charges 6,000 
pounds. We used limestone for a flux; for every 
three tons we used about 90 pounds, placed on top of 
every charge. There is no doubt that one or two 
hundredweight of slag could be added to the totals 
given above, which could be gathered from the skim¬ 
ming of the ladle and the dropping of the bottoms. 
Our apprehension as to loss of iron through slag was 


322 


METALLURGY OF CAST IRON. 


allayed when we discovered it was less than one-half 
of one per cent. 

The loss of pig iron through oxidation in the cupola, 
iron in the slag and refuse wheeled out from under the 
bottom, etc,, by melting in a cupola, will range from 
three to six per cent, of the total weight charged. The 
more sand scale on pig iron, the greater the loss. 
Unbroken pig iron will show a greater loss than broken, 
for the reason that the jar of breaking it over an iron 
block loosens the sand scale so that when the iron is 
thrown into a car for shipment from the furnace yard 
the purchaser receives less sand scale on his pig iron. 

Loss of scrap iron by melting in a cupola is given 
in Table 66, page 314, and discussed on pages 316 to 
318. This shows that the loss of stove plate may range 
from ten to fifteen per cent, or more and heavier scrap 
from four to eight per cent, or more, according to the 
scale and dirt conditions of the iron. 

We can look to oxidation for much of the total loss 
incurred by remelting iron. There is little doubt but 
that most of the loss by oxidation is done above the 
tuyeres, as the metal is dropping from the melting 
point through the fuel down past the tuyeres to the 
bath of metal in the bottom, and from the surface of 
the solid metal, at or above the melting point, as it 
exposes a semi-molten surface to the effects of the blast. 
The more surface we expose to the effects of blast the 
faster the oxidation, hence, with light scrap, we must 
expect the greater loss. There are reasons why one 
founder should lose 10 percent, and another only 3 per 
cent., in remelting cast iron. It will pay any founder 
to closely investigate his losses, and he may often lessen 
them by intelligently understanding the cause. 


CHAPTER XLVII. 


COMPARATIVE FUSIBILITY OF FOUNDRY 

METALS.* 

In the advance of founding to a basis of greater 
exactness and assurance of successful workings, it is 
often as essential for us to have information on the 
fusibility of the metals we make mixtures from, as to 
know the effect of one metalloid upon another in 
changing the physical character of iron. This is real¬ 
ized when we consider how easily a formulated mixture 
can be prevented from giving calculated results, by 
one metal having a lower fusing point than another 
when charged into a cupola. While this is a subject 
of importance to the general and heavy-work founder, 
who is often called upon to take several different 
grades out of a cupola at one “ heat,” it is also of im¬ 
portance to the specialty and light-work founder who 
may be charging irons of different grades to make 
one or two mixtures for a whole heat, for when 
the latter knows that one combination of certain metal¬ 
loids requires greater heat than others he is in a much 
better position to decide whether it is the iron, blast, 
atmosphere, fuel, mischance, or his own mismanage- 

*This chapter comprises two papers, revised for this work, 
which the author presented respectively to the Pittsburg Foun- 
drymen’s Association in June, 1897, and to the Western Foundry- 
men’s Association at Cincinnati, in October of the same year. 



324 METALLURGY OF CAST IROjn. 

ment that makes the cupola irregular in its meltings 
so that it produces hot'iron one day and dullish iron 
the next, also harder iron than desired with resulting 
bad work or heavy losses in castings. Knowing how 
very important it is to possess definite knowledge 
concerning what causes grades of iron to differ in their 
fusibility, I decided to experiment and learn, if pos¬ 
sible, the effect of different combinations of the metal¬ 
loids on the fusing point of iron. In searching for 
appliances that would give reliable data I failed to 
find anything satisfactory, and therefore set to work 
to devise something that would meet the requirements 
and at the same time withstand criticism. One objec¬ 
tion I have to past methods of testing the fusibility 
of metals, is the failure to provide conditions similar to 
those used in actual founding. To meet the con¬ 
ditions of actual practice, I studied out a design of 
cupola (see Fig. 56, page 241) which is an original 
arrangement, so far as I know. The method 
adopted gives only comparative results and does 
not show the degree of heat required to fuse any 
of the metals. Observations may be made and con¬ 
clusions drawn from them as to the difference in the 
time of melting which any grade of metal requires 
over another, when the two kinds of iron are charged 
in the respective sides shown. It will appear upon 
examination that like conditions must prevail in both 
apartments, and that if one grade starts or comes down 
quicker than another we know it to have a lower fusing 
point. By a series of such tests we are in position to 
formulate a scale showing the combinations of metal¬ 
loids requiring the highest heat, with the relative 
gradations of others, down to that most readily fused. 


COMPARATIVE FUSIBILITY OF FOUNDRY METALS. 325 

The comparative test cupola seen on page 241 is not 

an expensive affair, and is such as might often be a 
valuable adjunct to the laboratory of metallurgists, 
blast furnaces, foundries, etc., besides being useful 
for the production of repairs for breakdowns, etc., 
and then again for small castings, which it may be 
desirable to make of two separate grades of metal. It 
will be well to state that, where only one kind of iron 
is desired to be melted the center blast can be closed 
and the iron made to run to one tap hole by having 
one slanting bed as in regular cupola practice. 

In designing the cupola (Fig. 56) I arranged for a 
center blast, besides having outside tuyeres on the plan 
shown. This permits the greatest possible uniformity 
of combustion throughout the area of the cupola and 
affords every opportunity of regulation should the heat, 
from any cause, be greater in one portion than in 
another. This regulation is secured by diminishing or 
increasing the volume of blast by valves attached to 
branch pipes, not shown, leading to the tu3^ere open¬ 
ings A A, B B, and E. It may be asked, How is it 
possible to know when there is perfect uniformity of 
heat all over the area of the cupola? This is indicated 
by the color of the flame emanating from the open top 
of the cupola. If any difference should exist there on 
either side, the eye will detect it as quickly as the steel 
maker can note changes taking place in a Bessemer 
converter by means of the spectroscope. 

In operating this cupola the sand bed is put in with 
two slanting bottoms, as seen at H H, thus preventing 
either metal, as it comes down, from mingling with 
the other. The center tuyere has three pieces of 
^-inch round iron laid over its opening, as seen at M, 


3 2 6 


METALLURGY OF CAST IRON. 


to prevent the fuel from dropping into it and stopping 
its blast passage. Good kindling is used up to within, 
say, 12 inches of the top. On this, coke broken to about 
double egg size, is then placed. The coke is poked 
down as the fire burns until there is a solid bed of live 
coals up to within 15 inches of the top. If the metal 
to be fused is of a light character, or easily melted, it 
is then charged at this height; but if it is heavy or 
hard to liquefy, then the bed of live fuel should extend 
up to about 12 inches from the top, as shown by the 
pigs at X. As this cupola has ample tuyere area evenly 
divided, it can be worked with a mild or strong blast, 
as may be desired. The tap holes at D D are left open 
so as to permit the metal to flow out as fast as it melts, 
thus allowing a record to be made of the metal’s first 
and last appearance. Of course, should the cupola be 
used simply for the purpose of melting to get metal to 
pour a casting, it could then be stopped and tapped 
the same as any cupola used in ordinary practice. . If 
the cupola is employed for testing the comparative 
fusibility of metals, it may often require about six 
men to operate it — one for timekeeper, one to charge 
on fuel evenly and press it down so as to preserve a 
solid fire until the iron is about half down, one at each 
tap hole to keep it open that the metal may flow freely, 
and then, if the metal is to be caught into moulds, two 
men on each side to take away the filled moulds and 
replace empty ones. If the cupola is only to be used 
to obtain metal to pour a small casting, or to record 
the time of fusing by letting the metal down into a 
ladle or “ pig ” as it comes out, then two men are 
sufficient to operate it. In charging any metal for a 
comparative test, care must be exercised to have the 


COMPARATIVE FUSIBILITY OF FOUNDRY METALS. 327 

bed of the fuel the same height on both sides, also to 
have each grade of metal as nearly uniform in size as 
possible, and evenly charged. After this, coke is filled 
in until the eupola is stocked to its brim, when it is 
ready for the blast. 

The first test heat made, as seen by the Table 70, 
consisted of 150 pounds on each side, it being put in 
with 50 pounds in two charges after the bed of 50 
pounds was on. This plan was found to be objection¬ 
able for comparative testing, as it showed wherein 
errors might easily be made by reason of uneven 
charging, the escaping flame making it too hot for the 
charger to always place the iron in evenly. After this 
first heat no more metal was charged than the bed 
could carry well, thus permitting all iron to be care¬ 
fully charged before the blast went on. The plan 
adopted for comparative tests of Table 70 was to make 
at least two casts of each grade, the first being that of 
the metal in its original state, each grade being broken 
to uniform size, as far as possible. This, in being 
melted down, was run into moulds that gave blocks 
weighing about 15 pounds each and in size 2^ X4X6 
inches. For the second cast of each grade these 
blocks, in the larger heats, were broken in two pieces, 
but where there were only two blocks for each side 
they were charged whole. The idea of running the 
first heat of pig metal or scrap into blocks, as stated, 
was to obtain metal that would be closely uniform in 
size and weight and better insure like conditions in 
making a comparative test, an important requisite. 
This appears in Table 70, in the columns marked 
alternately “ pig ” and “ block.” Up to the time of 
writing this paper I have made nineteen comparative 


328 


METALLURGY OF CAST IRON. 


tests, but only give results of eight of them here, for 
the reason that in the case of the others I desire to make 
experiments that will require much time, and that 
should be compiled with the second series to give 
complete results in that line of inquiry. As the first 
series of tests is distinct, in showing what effect low 
silicon and high sulphur have upon the fusibility of 
iron, as compared with high silicon and low sulphur 
with the total carbon and the “ iron ” closely constant, 
I permitted the appearance of this paper at the re¬ 
quest of the secretary. The second series of tests 
is given in pages 332 to 344. 

TABLE NO. 70—COMPARATIVE FUSING TESTS OF HIGH AND LOW SILICON 

AND LOW SULPHUR IRONS. 


“Heat” Nos. 

1 

2 

3 

4 

5 

6 

7 

8 

Form of iron charged 

Pig. 

Block. 

Pig. 

Block. 

Pig. 

Block. 

Pig. 

Block. 

Weight of iron 
charged each side.. 

150 

65 

100 

54 

40 

35 

64 

50 

Blast turned on. 

L 55 

i :35 

2:13 

2:08 b 

4:21 

1:56 

1:44 

2:26 

Harder iron running 

U 57 

U 39 

2:21 

2:1214 

4:27 

2:02 b 

1:50 

2:32b 

Softer iron running.. 

U 57 b 

1:40 

2:2114 

2:13b 

4:28 

2:02 

1:50 b 

2:34 b 

First mold of harder 
iron filled... 

i :59 

1:42 

2:24 

2:16 

4:31b 

2:06b 

2:55 

2:37b 

P'irst mold of softer 
iron filled. 

2:01 

i :43 

2:24 

2:15b 

4:32b 

2:07 

2:55 b 

2:38 b 

Second mold of 
harder iron filled... 


U 43 

2:26 

2:17 

4:36 


2:57 

2:40 

Second mold of softer 
iron filled. 


1:44 

2:26 

2:16b 

4 : 38 b 


2:58 

2:41 

Third mold of 
harder iron filled... 


1:44 

2:27 b 

2:17b 





Third mold of softer 
iron filled... 

. 

U 45 

2:28 

2:17b 





Harder iron all down 

2:19b 

1:49 

2:37 54 

2:18 

4:37 

2:09 b 

2:02 b 

2:47 b 

Softer iron all down. 

2:22 

1:50 

2:39 

2:1854 

4:40 

2:11 

2:05 

2:48 b 

Time of melting. 

25m. 

nm. 

i6^m. 

6m. 

13m. 

10m. 

15m. 

I 5 b m - 

First iron to melt. 

Hard. 

Hard. 

Hard. 

Hard. 

Hard. 

Hard. 

Hard. 

Hard. 

Time exceeding its 
mate. 

45 s. 

1 m. 

10 s. 

45 s. 

1 m. 

15 s. 

im 30s 

im 45s 

First iron all down... 

■ Hard. 

Hard. 

Hard. 

Hard. 

Hard. 

Hard. 

Hard. 

Hard. 

Time exceeding its 
mate. 

2 m 30s 

1 m. 

1 in 30s 

30s. 

3 m - 

im 30s 

2m 15s 

1 m. 

























































































































































































COMPARATIVE FUSIBILITY OF FOUNDRY METALS. 329 


TABLE 71.—CHEMICAL ANALYSIS OF TABLE 70. 


Analysis Letter. 

A 

B 

C 

D 

Total Carbon. 

4-25 

4-03 

4 -i 5 

4.10 

Graphite Carbon. 

2.07 

1.76 

1.94 

3-92 

Combined Carbon. 

2.18 

2.27 

2.21 

.18 

Silicon. 

•85 

.92 

•99 

2.70 

Sulphur. 

.21 

•19 

•17 

•03 

Manganese... 

.18 

•17 

.26 

-34 

Phosphorus. 

.192 

.129 

.655 

.085 

Iron by difference. 

94-32 

94-56 

93-77 

92-74 


The importance of this work will be better under¬ 
stood when it is stated that at the present time (1897) 
some are laying claim to tests proving that soft grades 
of all irons will melt down faster than hard irons. The 
contrary results have chiefly been my experience, and 
appear to be the general expression on this question. 
Still, I hold, as stated in the early part of this paper, 
that results are often affected by combination of the 
metalloids as well as by the physical character of the 
iron, and I believe my second paper will bear me out 
in this assertion. I desire here to thank Dr. Richard 
Moldenke and the McConway & Torley Co. of Pitts¬ 
burg for the assistance rendered me in this work by 
furnishing metals and complete analyses of the irons 
shown. 

Referring to the preceding tables, attention is first 
called to the analyses. The column under A, Table 
71, is that of hard iron in heats Nos. 1 and 2. B is 
that of a white iron used for heats Nos. 3 and 4, C is 
that of a mottled iron used for heats Nos. 5, 6, 7, and 
8, while D is the analysis of a soft iron used as a com¬ 
parative constant to the hard irons throughout the 
eight heats. It may be stated that drillings for 



























































33 ° 


METALLURGY of cast iron. 


analyses were all taken from the blocks as they came 
from the first casts of the original pig or scrap metal. 

In all the heats the hard iron is seen to have come 
down first, excepting in one case which is found in 
heat No. 6, and that the flow of hard iron ended 
soonest in all the heats. Thus, as far as these tests 
go they show that hard iron will melt faster than soft, 
and confirm my past assertions and the general impres¬ 
sion existing among old experienced founders that 
hard iron will melt more readily than soft grades. 

An interesting discussion followed the reading of 
the paper. Dr. Richard Moldenke contributed the 
following: “ Long experience with the melting of iron 
in Siemens-Martin furnaces having given me the 
impression that hard irons melt faster than soft ones, 
and knowing this to be the accepted view among the 
trade, I was not a little astonished to see claims 
advanced insisting on the contrary. At the time I 
thought it likely to be owing to some radical difference 
in the composition of the irons that were used, and was 
therefore more than pleased to hear Mr. West advance 
the idea of making comparative tests to settle the 
matter definitely. It has remained for him to devise 
a most excellent system of melting to accomplish this 
result, and I, for one, have been much interested in 
the working of his “ twin shaft cupola ” (Fig. 56), if I 
may so call it. It will give us ready means of com¬ 
paring the fusibility of the required brands of iron 
going into our cupola charges. The few words I have 
to add relate to the melting of iron in the open-hearth 
furnace, where there is obviously no difficulty due to 
the rate of melting, since everything charged is sup¬ 
posed to make up a bath of uniform composition. I 


COMPARATIVE FUSIBILITY OF FOUNDRY METALS. 33 1 

made two experiments, charging simultaneously in 
each case two pigs of equal weight and shape, one 
being soft, the other hard. It will be observed that in 
the open-hearth furnace, filled up with a charge just 
melting down, these two pigs thrown on top of the 
white hot metal, and in the full head of the furnace, 
could be closely watched with the aid of blue glass 
spectacles. In the first experiment I was surprised to 
find the soft pig melting first. It became soft and 
could be broken up by the bar, behaving much like a 
plumber’s wiping metal when it is just soft enough to 
work. This soft pig, when thus crushed, looks like 
silver, and makes one wish for time and opportunity 
to study the characteristics of the carbons while in this 
state. The hard pig, on the contrary, retained its 
form remarkably well, not disintegrating like the soft 
one did, the melted portions dropping off like water. 
Further investigation developed the fact that the soft 
iron which melted first was about 55 points higher in 
the total carbon than the hard iron. (The author held 
that difference in the graphitic and combined carbons 
would affect results as seen on pages 154 and 329.) 
Mr. West, in his second paper, will go into this question 
fully, as he is making extended experiments in this 
line. The other trial was with two irons of the same 
brand, shape, and weight. They had very nearly the 
same manganese, sulphur, phosphorus, and total car¬ 
bon, but one had twice as much silicon as the other, 
resulting in 3.37 percent, graphite in the soft pig, and 
only .68 per cent, in the hard white one. In melting 
these two pigs under exactly the same conditions, 
the hard one went first. It held its form well, but 
in melting ran like water, and was melted before 


33 2 


METALLURGY OF CAST IRON. 


the soft iron was half gone. The soft iron melted 
sluggishly, and did not hold its form while melting as 
well as the hard iron. It was very interesting, even if 
trying to the eyes, to observe the whole process, and 
now that Mr. West has gone into the whole matter 
so thoroughly, we will certainly be able to crystallize ( 
our ideas and know what we may look for in making 
up important charges. ’ ’ 


REVISION OF SECOND PAPER ON FUSI 
BILITY OF FOUNDRY METALS. 

This second paper, aside from presenting several 

important discoveries made by the author, shows that 
a chilled body of iron will melt faster and require less 
heat than a gray body, both having been poured from 
the same ladles or cast of iron, and that steel proper 
requires higher heat than cast iron to fuse it; also that 
remelting of steel in contact with incandescent fuel 
wholly destroys its original character. Making com¬ 
parisons of the fusibility of gray and chilled bodies, 
both of the same composition excepting the combined 
carbon, was accomplished by the following plan. A 
heat of chilling or low charcoal iron, designated as 
heat No. 9, Tables 72 and 73, was caught in hand ladles 
and then poured into sand and chill moulds, placed 
side by side. A view of the chill mould and chill roll 
cast in it is seen at Figs. 58 and 59, page 312. This 
gives a wholly gray body of iron in the casting coming 
from the sand mould, and a wholly chilled or white 
crystallized body of iron from the chill or all-iron 
mould; both, it is to be remembered, being poured 


COMPARATIVE FUSIBILITY OF FOUNDRY METALS. 333 


from the same ladle of iron. The fractures of the 
gray and chilled iron are shown in Figs. 61 and 
62, this page and 337. 

The gray and sand rolls which were used in these 



FIG. 6l.—GRAY ROLL. 

Combined Carbon, 1.20. Graphitic Carbon, 2.90. 

comparative tests were all tumbled, so as to get the 
sand off them thoroughly before they were charged. 
Before explaining the results and tests shown by Tables 
72 and 73, next page, we will describe the plan fol¬ 
lowed in conducting the heats shown: 

For heat No. 9, Table 72, charcoal pig iron was charged 
in both chambers of the cupola and run out of one tap 







TABLE 72 .—COMPARATIVE FUSION TESTS OF GRAY AND CHILLED IRONS. 


334 


METALLURGY OF CAST IRON 


0 

CN 

•siio-i piip P UB p«^s 

C/5 

& 

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10 

IO 

CN 

Tl" 

to 

to 

Tt* 

to 

to 

00 

to 

Td“ 

H\ 

ON 

to 

Tf- 

C/5 

O 

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Heat Nos. 

Kind of Metal Charged. 

Weight of iron charged 
each side of cupola... 

Blast put on. 

bi 

c 

•rH 

C 

C 

3 

)-c 

f- 

0 

U 

V 

• r- 

A 

U 


Gray iron running. 

Chilled iron all down. 

Gray iron all down. j 

Chilled iron exceeded 
crrav in starting__ 

) 

■> 

0 

Chilled iron exceeded 
prav in finishing.. 

0 






































































































































































COMPARATIVE FUSIBILITY OF FOUNDRY METALS. 335 


TABLE 73.—CHEMICAL ANALYSIS AND SPECIFIC GRAVITY OF GRAY 
AND CHILLED IRONS RAN FROM HEATS SHOWN IN TABLE 72. 


Heat Nos. 

j 

9 

IO 

II 

12 

Analysis of Castings 
obtained from the 
12th heat. 

Kind of 
metal 
charged. 

Char¬ 
coal pig 
| iron. 

Sand 

Rolls. 

Chill 

Rolls. 

Sand 

Rolls. 

Block. 

Chill 

Rolls. 

Block. 

Sand 

Rolls. 

Chill 

Rolls. 

Sand 

Rolls. 

Chill 

Rolls. 

Sand 

Rolls. 

Chill 

Rolls. 

Analysis 
letter. 

A 

B 

C 

*D 

*E 

F 

G 

H 

I 

J 

K 

Total 
Carbon... 

3-94 

4.10 

4.06 

4-30 

4-30 

4-47 

4.40 

00 

VO 

Tj- 

4.62 

4.76 

4.70 

Graphitic 

Carbon... 

3.06 

2.90 

0.16 

2.42 

2.68 

2.90 

0.20 

2.67 

0.00 

3.16 

0.03 

Combined 
Carbon . 

.88 

1.20 

3-90 

1.98 

1.62 

i -57 

4.20 

2.01 

4.62 

1.60 

4.67 

Silicon. ... 

.82 

• 75 

• 75 * 

•63 

.68 

.66 

•63 

•57 

•56 

•59 

•57 

Sulphur.... 

.02 

•03 

•03 

.04 

•035 

.04 

.04 

•045 

.046 

.048 

.044 

Manganese 

.78 

.66 

.66 

•53 

•54 

• 3 i 

•33 

.18 

.19 

•25 

.22 

Phos¬ 
phorus.. , 

.232 

.248 

.240 

.274 

.285 

•237 

.254 

•254 

.250 

.271 

.266 

Specific 

Gravity... 

7.01 

7 - 3 ° 

7.61 

7-35 


7.40 

7.70 

7-47 

7.76 

7.46 

7-79 


hole, the metal being poured into sand and chill moulds 
from one ladle. For heat No. io the sand and chill 
rolls from heat No. 9 were charged in their respective 
sides and the two tap holes used. The iron as it ran 
from this heat through open tap holes dropped into 
sand moulds, one being set under each tap hole, to 
give a block of iron from each side about six inches 
diameter by six inches high. This tenth heat had both 
sides run into sand moulds for the purpose of learning 
which would be the harder iron when remelted, that 
which had been chilled or that which had not. Heat 
No. 11 melted down the gray blocks obtained from 
heat No. 10, and this iron was again run into sand and 
chill moulds. Heat No. 12 was a remelt of the sand 
and chill rolls obtained from heat No. 11, and was the 

*The analyses D and E of the grey blocks coming from the sand and chilled 
rolls cast in heat No. io and melted down in heat No. ix is also shown at A2 
and B2, Table 74, page 336. 

































































































































33 6 


METALLURGY OF CAST IRON. 


fourth and last heat of a continuous remelt of the orig¬ 
inal charcoal pig used in heat No. 9. The metal from 
heat No. 12 had each side poured into sand and chill 
moulds, and the analyses at H, I, J, and K, Table 73, 
show the chemical changes made by the twelfth heat. 
Heats 13 and 15 were casts in which the same grade of 

TABLE 74.—CHEMICAL ANALYSIS OF CHILLED AND GRAY IRON RE-MELTS, 
POURED INTO SAND MOLDS BY HEATS SHOWN IN TABLE 72, PAGE 334. 


Description of 
iron and 
heat No. 

Analysis of 
gray blocks 
obtain ed 
from 10th 
heat. 

Analysis of 
gray blocks 
obtained 
from 16th 
heat. 

Analysis of 
gray blocks 
obtained 
from 18th 
heat. 

Analysis of 

chilled and 

sand rolls 

charged on 

20th heat. 

Analysis of 

gray blocks 

obtained 

from 20th 

heat. 

Classification 

of 

re-melts. 

Sand roll 
re-melt. 

Chill roll 
re-melt. 

Sand roll 
re-melt. 

Chill roll 
re-melt. 

Sand roll 
re-melt. 

Chill roll 
re-melt. 

Sand 
rolls as 
charged. 

Chill 
rolls as 
charged. 

Sand roll 

re-melt. 

Chill roll 

re-melt. 

Analysis Letter. 

A2 

B2 

C2 

D2 

E2 

F2 

G2 

H2 

I2 

J2 

Total Carbon.... 

4-30 

4-30 

4-30 

4 - 3 o 

2.94 

3 -i 5 

3-55 

3.60 

3-88 

3-95 

Graphitic C’rb’n 

2.42 

2.68 

2.20 

3.20 

2.41 

2-73 

2.63 

2.05 

2.15 

2.40 

Combined 
Carbon. 

1.98 

1.62 

2.10 

1.10 

•53 

.42 

.92 

1-55 

i -73 

i -55 

Silicon. 

•63 

.68 

• 75 

.87 

•55 

.69 

i -55 

i -57 

1.29 

i -39 

Sulphur. 

.04 

.035 

.04 

•°35 

•045 

.048 

.030 

.030 

.042 

.040 

Manganese. 

•53 

•54 

.48 

.62 

1.23 

1.32 

• 133 

•135 

.126 

.130 

Phosphorus. 

.274 

.285 

.283 

.241 

1.07 

1.07 

•343 

•330 

•364 

•350 


pig was used as in heat No. 9 as a check to learn if 
similar results would be obtained by further experi¬ 
ments, and heats 14 and 16 are used as a check on heat 
No. 10, in the same manner. 

The analyses given under A, B, and C, Table 73, for 
heats Nos. 9 and 10 will also serve for heats 13 to 16. 
When running the sixteenth heat the sand and chill 
roll metal was run into sand moulds, as described for 
heat No. 10. Heat No. 17 is a high manganese and 
phosphorus pig, which was run into sand and chill 
moulds to make rolls that were used for heat No. 18, 














































































































COMPARATIVE FUSIBILITY OF FOUNDRY METALS. 337 

from which the gray and chilled metals, as they came 
down, were both run into sand moulds. Heat No. 19 
is a No. 2 Foundry all-coke iron which was also run 
into sand and chill moulds. Heat No. 20 is made from 



Combined Carbon, 3.90. Graphite Carbon, 0.16. 

FIG. 62 .—CHILLED ROLL. 

the sand and chill rolls obtained from the nineteenth 
heat, both of which metals were run into sand moulds 
as heats Nos. io, 16, and 18. Analyses of the gray 
and chill roll remelts, that were poured into sand 
moulds to test whether chilled or grey parts of the same 
casting would give the softer iron, are all shown in 









338 METALLURGY OE CAST IRON. 

Table 74. The analyses A2 and B2 are also shown in 
Table 73, at D and E, page 335. 

It was the belief, until the author’s discoveries 
proved the contrary, that an iron once chilled would, 
upon being remelted, produce a much harder casting 
than if the same iron had never been chilled. This 
belief was so strongly maintained by founders, prior 
to the author’s discovery, that in selecting scrap iron 



GRAY ROLL. FIG. 63. CHILLED ROLL. 

for mixtures with pig metal to make light or heavy 
machinery castings, etc., founders would reject the 
scrap that had been chilled, if it could be done, lest it 
might cause hard spots in a casting or make the whole 
too hard. Of course, it is to be understood that if a 
casting shows a chill, it is evidence that the gray body 
of the casting, if used for scrap, is not accepted as a 
soft iron, as if no part of the casting exhibited a chill; 
for, as a rule, founders know such fractures are not to 
be graded as soft iron. Nevertheless, they did not 













comparative fusibility of foundry metals. 339 

know that a chilled iron body would give a casting 
slightly softer than if the chilled part had been rejected 
and only the gray body utilized. While this knowl¬ 
edge would always have been of much value to the 
founder, there has been no time that it could be turned 
to more profitable account than at the present. It 
may be asked what evidence there is aside from the 
drilling tests to prove that the chill roll remelt was 
softer than that of the gray. This is .answered by 
referring to the columns B2, D2, F2, and J2, Table 74, 
and noting the greater silicon and graphitic carbon 
existing in the chill remelt than is found in the gray, 
as seen at A2, C2, E2, and I2. The author’s attention 
was first drawn to the fact that the chill remelt was 
softer than that of the gray, by drilling to obtain 
material to make the analyses. The drill worked so 
much easier in the chill remelt than in the gray as to 
be a matter of much surprise. The drill press used is 
shown at Fig. 53, page 239. After a well sharpened 
twist drill was attached and all ready, the drill was 
started and allowed to run exactly half a minute. By 
drilling several holes in the manner described on page 
234, alternately in each of the respective blocks, we 
could then, by measuring their depth, intelligently tell 
which of the two was the softer. It is to be said that 
the drillings of the whole four heats, Nos. 10, 16, 18, 
and 20, showed the chill remelt to be softer than those 
of the gray iron. It will be noticed also that these 
four remelts are distinct in testing different grades of 
iron, so as to cover a wide range of metals, from those 
that would take but a slight chill on the surface of pig 
metal or a casting up to those that would chill its whole 
body as displayed in Fig. 62. 

Attention is again called to the specific gravity tests 


340 


METALLURGY OF CAST IRON. 


seen in Table 73, page 335, which, in four successive 
remelts, raised the density of the gray iron from 7.01 
to 7.46, an increase of .45 in density, and in the chilled 
iron to 7.79, an increase of .78 from the original pig, 
showing that successive remelts greatly increase the 
density of irons. Another point to be noticed is that 
the chilled iron differs about .30 in density from the 
gray iron in the respective heats shown. For a com¬ 
parison of the specific gravity of other metals with cast 
iron, see Table 136, page 593. 


TABLE 75.—COMPARATIVE FUSION TEST OF CAST IRON WITH OPEN 

HEARTH STEEL. 


Heat Nos. 

21 

22 

23 

24 

25 

26 

27 

28 

Kind, Weight 
and Form of 
Metal Charged 
Each Side. 

35 lbs. of iron 
and steel in 
block form. 

29 lbs. of iron 
and steel in 
block form. 

23 lbs. of iron 
and steel in 
block form. 

61 lbs. of iron 
and steel in 
scrap form. 

44 lbs. of iron 
and steel in 
block form. 

52 lbs. of iron 
and steel in 
scrap form. 

40 lbs. of iron 
and steel in 
block form. 

58 lbs. of iron 
and steel in 

block form. 

Blast put on. 

8:56 

2:50 

3:00 

11:30 

3:23 

10:37 

. 11:29 

3:26 

Steel running.. 

9:09 54 

2:5954 

3:05 

11:4154 

3:32 

io: 45 K 

h :3854 

3:32 

Iron running... 

9:0614 

2:58 

3:04 

11:38 

3:3054 

10:45 

11:3654 

3:3254 

Steel all down. 

9:21 

3:08 

3 :u 54 

11:51 

3:4154 

10:5854 

ii :4954 


Iron all down.. 

9:1 754 

3:0554 

3:10 

11:48 

3:40 

10:58 

11:49 


Iron exceeded 
steel in start¬ 
ing . 

3m. 

im. 30s. 

im. 

3m. 15s. 

im. 30s. 

45 S. 

rm. 30s. 

15s. 

Iron exceeded 
steel in fin¬ 
ishing. 

3m. 30s. 

2m. 30s. 

im. 15s. 

3m. 

im. 15s. 

30s. 

45 S. 



Chemical changes due to remelting iron. In a study 
of Table No. 73 we are first struck by the increase of 
total carbon. We find that starting with the original 
pig containing 3.94 carbon, four re-melts increased it 
to 4.76, an increase of nearly one per cent: It is to be 
noted that in all cases the sand or gray rolls show more 
carbon than the chilled roll. 


























































































COMPARATIVE FUSIBILITY OF FOUNDRY METALS. 34I 


TABLE 76.—CHEMICAL ANALYSIS OF GRAY CAST IRON AND OPEN 
HEARTH STEEL RE-MELTS GIVEN IN TABLE 75, OPPOSITE PAGE. 


Heat Nos. 

21 

22 

23 

Analysis 
of metal 
obtained 
from the 
23d heat. 

Analysis of 
metals 
charged in 
heats Nos. 
24 to 26. 

Kind of Metal 
Charged. 

Gray cast iron. 

Open-hearth steel. 

Gray cast iron. 

Open-hearth steel. 

Gray cast iron. 

Open-hearth steel. 

Gray cast iron. 

Open-hearth steel. 

Gray cast iron. • 

Open-hearth steel. 

Analysis letter 

L 

M 

N 

O 

P 

Q 

R 

S 

T 

U 

Total carbon... 

4.02 

.60 


1.48 


2.74 

4.60 

3-05 

4.20 

.70 

Graphitic 











carbon. 

2.90 




........ 

....... 

3-30 

•15 

3-03 

trace 

Combined 











carbon. 

1.12 

.60 


1.48 


2.74 

1.30 

2.90 

1.17 

.70 

Silicon. 

1.72 

•31 


.26 


.14 

I - I 5 

•35 

1.24 

.38 

Sulphur. 

•03 

.026 


. 10 


.14 

.10 

.18 

•05 

.12 

Manganese 

•35 

•34 


•23 


• 15 

•23 

.06 

.40 

•59 

Phosphorus.. .. 

•073 

. 106 


. 167 


. 190 

.103 

. 198 

.092 

.116 


The effect of remelting upon the silicon, sulphur, 
manganese, and phosphorus is well shown in Tables 
73, 74, and 76. We find the results are all in line with 
the varied experience of those who have kept close 
watch of remelts, to the effect that silicon and man¬ 
ganese decrease while sulphur and phosphorus increase. 
It may cause some surprise that more silicon was not 
lost or sulphur added than shown by the four continu¬ 
ous remelts in heats Nos. 9, 10, n, and 12, Table 73. 
The author accounts for this in that the metal was held 
in the cupola but a short time, compared to that gen¬ 
erally occupied in ordinary shop practice. The longer 
heated or semi-molten iron remains in contact with 
incandescent fuel or is exposed to gases, the more 
sulphur will be absorbed — up to the limit of the iron’s 
























































































































342 


METALLURGY OF CAST IRON. 


absorptive power. The reverse is true of silicon, as the 
longer the iron is exposed to the effects of high heat 
and blast, the more silicon is lost. 

STEELY IRON CASTINGS. 

Remelting steel requires longer time to fuse than 
cast iron, as will be seen by Table No. 75, page 340, 
in which heats Nos. 21, 22, and 23 are continuous 
remelts of the same metals. The steel was a “ riser- 
head ’ ’ piece of scrap that was moulded to make a 
single piece of cast iron of the same form, so that con¬ 
ditions as to form and weight could be the same for 
both metals in making the comparative fusing test 
shown. Heats 24, 25, 26, and 27 are two remelts of 
different quantities of cast iron and steel metals, hav¬ 
ing similar composition, as will be noted by referring 
to columns T and U, Table 76, page 341. 

Heats 24 and 26 had the metals in scrap form as 
nearly alike in size and bulk as they could be roughly 
made, and when melting they ran into moulds to give 
blocks 2X4 x 6 inches, so as to insure a uniform size 
of stock for making the comparative heats 25 and 27. 
Heat 28 was a remelt of the blocks obtained from heats 
25 and 27. In this heat, it will be noticed, the iron 
and steel came down closely together. The reason 
the closing time is not shown is on account of stopping 
up the tap holes after the iron had started to run, with 
a view to catching metal in a hand ladle to pour 
shrinkage and contraction tests (see page 410), which 
left the matter too indefinite to record the time of 
actually finishing first, although, as near as we could 
see or judge, they ended closely together. Table 75 


COMPARATIVE FUSIBILITY OF FOUNDRY METALS. 343 

shows that the more we remelt steel scrap the less 
difference exists in the iron starting and closing ahead 
of the steel. This is due to the fact that remelting 
steel raises its total and combined carbon and at the 
same time we find that steel remelts will be very 
spongy or filled with gas or blow-holes, which increase 
more in size and number with each successive heat, 
thus causing the steel product to be very porous and 
thereby permitting the heat to better penetrate its 
body and bring it quicker to a fluid state. 

Table 76 shows the folly of trying to remelt steel 
and obtain from it the original metal, as can be closely 
done with cast iron. Nothing has led founders on 
more wild-goose chases than giving ear to some of the 
high-sounding claims made for remelts of steel or its 
mixture with cast iron. It is true that steel scrap 
mixed with cast iron can strengthen the latter to a 
limited degree, but the extreme claims some make for 
its mixture with cast irons are erroneous and unfounded. 
We have no metal that will deteriorate from its orig¬ 
inal state by reason of remelting, so much as steel 
scrap. The action taking place in remelting steel in 
a cupola increases the carbon in the metal, as shown 
in Table 76. We find that the first remelt raised the 
carbon from .60 to 1.48; the second sent it up to 2.74, 
and the third to 3.05—an increase in either of these 
three remelts sufficient to show that we are very far 
from retaining anything like the original steel in any 
remelts in a cupola which compels the steel to be in 
contact with the fuel from which it absorbs the carbon 
with avidity. 

When steel is melted in a reverberatory or air fur¬ 
nace, in mixture with cast iron, we have more favor- 


344 


METALLURGY OF CAST IRON. 


able conditions because of its being possible to keep 
the carbon lower and the better to add other metals, 
as spiegel and ferro-manganese, which alloy with the 
fluid metal without having their original properties 
destroyed to any great degree. Tensile strengths 
ranging from,45,000 to 50,000 pounds per square inch 
have been obtained by air furnace meltings with mix¬ 
tures of iron, steel, etc., but to obtain castings equal 
to those of steel proper we must have them cast by 
regular steel founders. Whenever we desire to improve 
the strength of cast iron by mixture with steel, the 
lower carbon or soft steels will be found to give the 
best results, and air furnace meltings excel those of a 
cupola, especially if charcoal irons are used. In mix¬ 
tures with the latter, from 15 to 30 per cent, of soft 
steel scrap may often be advantageously used. For 
further information on the steel question, see pages 265, 
267, 271, 272 and 276, and the “ Moulder’s Text-Book.” 

•- • 

THE MELTING POINT OF CAST IRON. 

The following is an extract of a valuable paper which 
was presented by Dr. Richard Moldenke before the 
Pittsburg Foundrymen’s Association, Oct. 24, 1898. 
This extract gives a description of the pyrometer which 
the doctor used for testing the temperature of molten 
metal, etc., and of its value in other lines, also of tests 
he made as found in Tables 77 to 81. In looking about 
for a pyrometer, the doctor’s attention was naturally 
directed to the latest and admittedly the best form of 
a pyrometer for very high temperatures — the Le 
Chatelier. In referring to this instrument and to his 
tests, the doctor says: “ This pyrometer consists essen- 


THE MELTING POINT OF CAST IRON. 


345 


tially of two pieces of wire of a slightly varying com¬ 
position, a heating of the junction of which produces a 
current of electricity proportioned to the degrees of heat 
applied. The amount of this current is measured by 
a suitably calibrated galvanometer, and thus we can 
read off the heat at any convenient distance rapidly 
and with a surprising degree of accuracy. 

“ Unfortunately, this wonderful instrument, one wire 
of which is of platinum, the other of an alloy of plati¬ 
num and io per cent, of the rare metal rhodium, cannot 
be immersed directly in the melted iron — there would 
soon be an end to this expensive thermo-couple. The 
long porcelain tube which protects it when used in 
kilns is worse than useless in a ladle full of metal, and 
so at the suggestion of the writer the Pittsburg repre¬ 
sentatives, the Vulcan Mfg. Co. set about to remedy 
the matter and devise some protective cover which 
would allow experiments of this kind to be carried out 
readily. The outcome, while not having the advantage 
as yet of an extended period of trial, was nevertheless 
so happy a solution that it is presented, for the first 
time, with the hope that much of value may be learned 
from it, not only in our daily work but also in connec¬ 
tion with the many intricate problems still before us 
which await solution at the hands of those willing to 
give their time and energy to such an exacting study. 

“Fig. 64 shows a section through the instrument. 
The platinum wire will be noticed running from the 
terminal box through an iron pipe ending at the inner 
side of the point of the clay tip. Here is the button 
made by the fusion to the other wire of platinum and 
rhodium alloy which runs back, parallel to the platinum 
wire, to the terminal box. Both wires are covered 



FIG. 65. —TWO FORMS OF LF. CHATELIER 
PYROMETER. 











































































THE MELTING POINT OF CAST IRON. 


347 


with asbestos to insulate them from each other and 
from the iron frame, as well as to serve as a protection 
in case the tip breaks while in the molten iron. The 



FIG. 66. — METHOD OF USING IN LADLE. 


interchangeable connection holding the clay tip allows 
it to point out straight for use in small ladles or in 
experimenting, or it may come down at right angles 
for taking temperatures in large ladles full of metal. 






348 


METALLURGY OF CAST IRON. 

A third form, not completed in time for illustration 
purposes, has a ball and socket joint which allows the 
tip to stand out at any angle. A movable shield lined 
with asbestos protects the hand. 



I 


FIG. 67.—APPARATUS FOR DETERMINING THE MELTING POINT OF CAST 

IRON — SIDE VIEW. 

“Fig. 65 shows two of the styles of the pyrometer, 
and Fig. 66 the method of using the angular form. In 
the terminal box are placed the connections which 
allow wires of any convenient length to run through 
the handle and connect with the galvanometer. The 
galvanometer itself is a * D’Arsonville, specially 











THE MELTING POINT OF CAST IRON. 


349 


gotten up and calibrated for industrial purposes. The 
original form with the reflecting mirror, and capable 
of reading to one-half of a degree at these high tem¬ 
peratures, was found too cumbersome and delicate for 
factory use. 

“The sensitiveness of the couple, even though pro¬ 
tected by a refractory material, is such that by plung¬ 
ing it cold into the melted iron the correct reading is 
obtained in one minute and three-quarters. When 
properly heated up to redness beforehand, however, 
this time is reduced to not many seconds. 

“ It would be beyond the scope of this paper to show 
the many uses to which such an instrument can be put 
in the steel and iron trade. On the question of 
annealing alone it will pay for itself in a short time. 

“We come now to the subject matter itself. You 
will all remember the recent discussion on the melting 
of white and gray irons, Mr. West’s elaborate experi¬ 
ments confirming our daily experience. Yet the cor¬ 
rectness of the conclusions were questions, and while 
the peculiar phenomena observed in the behavior of 
carbon with iron make any positive statements rather 
hazardous, yet the melting down of a lump of iron, 
and taking its temperature while doing so, should 
stand as a final determination of its melting point as 
viewed from the entirely practical side of the question. 
This is the consideration we have to deal with daily 
in cupola and furnace. 

“The material experimented with was gathered for 
several years, some of it being furnished by Mr. Jos. 
Seaman, Mr. Thos. D. West, and Mr. J. E. McDonald, 
members of this association, and the especially interest¬ 
ing alloys by Mr. R. McDonald, of the Crescent Steel Co. 


35 ° 


METALLURGY OF CAST IRON. 


“There were forty-eight pig irons, embracing both 
Foundry and Bessemer brands as well as softeners, 
made with coke and with charcoal, both cold and warm 
blast. Seven of the cast irons were of the shape seen 
at A, Fig. 67, being melted right from the tip. The 
balance of the fifteen specimens were of the sand and 
chill rolls made by Mr. West in his recent experi¬ 
ments.* Two steels and nine alloys of chromium, 
tungsten, and manganese, with iron, complete the list 
of seventy-three specimens. 

“The melting was done in an assay furnace converted 
for the time into a cupola. Fig. 68 gives a front view 
of it while in full operation. A jet of steam entering 
the stack in the side near the top induced the blast, 
the air being drawn in all around the bottom. In this 
form it is really the ‘ Herberz ’ cupola of European 
fame and excellent for small diameters. A hole was 
broken into the wall just below the charging door, 
which must be kept closed when not used. This hole 
allows the introduction of the pieces of pig iron, etc. 
After heaping up enough coke to last for some time, 
the piece of pig iron (of full section and about five 
inches long), was driven into the bed, surrounded by 
incandescent coke, and the opening closed with a tile. 
After it was red hot the tile was removed, the pyrom¬ 
eter inserted and pushed against the center of the 
pig where the borings were taken for the analysis. 
The temperature as registered by the pyrometer rose 
rapidly, then more slowly, remaining stationary while 
the iron melted slowly. Then as the point finally 
became uncovered the temperature jumped up, going 


* This refers to the experiments seen on pages 332 to 339. 



THE MELTING POINT OF CAST IRON. 


351 


above 2,600 degrees F. In this way the results noted 
in the tables below were obtained. 

“It took much patience, a loss of a few samples, and 
a number of broken tips to accomplish all this, but on 
the whole the results given are as good as could be 
gotten under the conditions prevailing. The coke 
burning up would let the iron drop a little, and a fail¬ 
ure to adjust the pyrometer to suit (the opening being 
closed by a piece of sheet iron, to prevent undue cool¬ 
ing by air drawn in), meant a break in the tip, which, 
while not affecting the results, caused subsequent delay 
and trouble. 

“The following general observations were made. 
The white irons held their shape, the iron running 
from the sides and bottom freely, leaving smooth sur¬ 
faces. The gray irons became soft, dropped in lumps, 
leaving a ragged surface. Ferro-manganese samples 
became soft and mushy, exhibiting a consistency of 
putty before finally running down. Ferro-tungsten 
behaved in the most marked way. As it melted it 
acted like white iron, but instead of chilling quickly it 
ran through the coke, coming down the spout in thin 
streams like white hot quicksilver, only setting after 
collecting in a pool in the pan of sand. (The above de¬ 
scription of melting points of white and gray irons 
was verified by other members, though under different 
conditions.) The cupola was fluxed heavily with fluor 
spar to take care of the ash, for it was a case of a 
furnace full of incandescent coke and only one piece 
of iron in it. ’ ’ 

The following tables give the results. For melt¬ 
ing points of other metals than shown in this chapter, 
see Table 134, page 593. 


35 2 


METALLURGY OF CAST IRON 


TABLE 77.—PIG IRONS. 


6 

£ 

Melting 

Point. 

Com. Car¬ 
bon. 

Graphite. 

Silicon. 

Manganese. 

Phosphorus. 

Sulphur. 

r 

2030°F. 

3-98 


.14 

.10 

.220 

•037 

2 

2040 

3 - 9 ° 

. 

.28 

.11 

.216 

.044 

3 

2040 

3-74 

.14 

•38 

.16 

.172 

.032 

4 

2070 

3-70 


.26 

.09 

.198 

•033 

5 

2100 

3-52 

•54 

•47 

.20 

.200 

.036 

6 

2040 

3-48 


.36 

.09 

•249 

.040 

7 

2055 

3.22 

.68 

• 7 1 

.09 

.142 

.038 

8 

2010 

3.21 

.20 

45 

.18 

.198 

.037 

9 

2110 

2.28 

1.14 

42 

• 13 

.185 

.026 

10 

2140 

2.27 

1.80 

•45 

1.10 

1.465 

.032 

11 

2150 

2.23 

1.58 

42 

.16 

•415 

•045 

12 

2170 

1.96 

1.90 

•75 

•63 

.097 

.028 

13 

2170 

i -93 

1.69 

•52 

.16 

.760 

.036 

14 

2170 

1.87 

1.85 

•56 

.46 

• 7 i 3 

.027 

15 

2150 

1.84 

i -95 

•56 

•34 

•175 

.022 

16 

2190 

1.72 

2.17 

1.88 

•54 

.446 

.028 

17 

2200 

1.69 

2.40 

1.81 

•49 

1.602 

.060 

18 

2230 

1.71 

2.08 

2.02 

•39 

.632 

.062 

19 

2190 

. i -49 

2.26 

2-54 

•50 

•349 

.038 

20 

2210 

1.48 

2.30 

1.41 

i -39 

.168 

•033 

21 

2190 

1.47 

2.63 

•89 

.48 

.164 

•037 

22 

2190 

1.36 

2.41 

1.65 

•32 

.160 

.038 

23 

2210 

I - 3 r 

2.70 

1.25 

.76 

.170 

.022 

24 

2210 

1.31 

2.40 

1.69 

.46 

.085 

•039 

25 

2230 

1.24 

2.68 

•65 

.26 

.201 

.020 

26 

2230 

1.23 

2.70 

1.20 

•37 

•299 

.022 

27 

2230 

1.12 

2.66 

1-13 

.24 

.089 

.027 

28 

2200 

.90 

3-07 

1.09 

•33 

.176 

.014 

29 

2230 

.87 

3.10 

i -34 

•42 

.158 

.030 

30 

2210 

.84 

3-07 

2.58 

•47 

2.124 

.051 

31 

2260 

•83 

3.26 

i -97 

■59 

.210 

.018 

32 

2230 

.80 

3.22 

1.30 

•59 

.172 

.042 

33 

2250 

.80 

3.16 

1.29 

•50 

.218 

.020 

34 

2250 

.80 

2.89 

2.21 

•25 

411 

.041 

35 

2250 

.67 

3.60 

1.32 

.20 

.205 

.020 

36 

2240 

•59 

3-15 

1.50 

.61 

.094 

.032 

37 

2230 

•47 

2.84 

2.19 

•65 

1.518 

.042 

38 

2250 

•38 

3-43 

2.44 

•57 

422 

.048 

39 

2250 

•35 

3-44 

2.07 

.28 

•448 

•039 

40 

2260 

•35 

3-70 

3-29 

.82 

.501 

.038 

4 i 

2260 

.24 

348 

2-54 

•30 

060 

.020 

42 

2280 

•13 

343 

2.40 

.90 

.082 

.032 


TABLE 78.—SOFTENERS, FERROSILICONS, AND SILICO SPIEGEL. 


43 

2190 

3-38 

•37 

12.30 

16.98 



44 

2040 

1.82 

. 47 

12.01 

1.38 



45 

2090 

2.17 

•72 

10.96 

i -34 



46 

2155 

i -35 

1.60 

9.40 

•32 



47 

2145 

1-57 

1.36 

8-93 

•39 



48 

2170 

1.77 

1.80 

4.96 

•39 


• 















































THE MELTING POINT OF CAST IRON. 


353 


TABLE 79.—CAST IRONS. 


d 

fc 

Melting 

Point. 

Com. 

Carbon. 

Graphite. 

49 

2000°F 

4.67 

•03 

50 

1990 

4.20 

.20 

5i 

2010 

4.08 


52 

2000 

3-90 

.16 

53 

2030 

3.62 


54 

2030 

348 


55 

2040 

340 


56 

2170 

1.63 

2.27 

57 

2210 

1.60 

3 -16 

5« 

2250 

i-57 

2.90 

59 

2240 

1.22 

2.66 

60 

2250 

1.20 

2.90 

61 

2260 

•17 

3-57 

62 

2080 

i -95 

1.28 

63 

2080 

1.81 

1.36 


Silicon. 

Manga¬ 

nese. 

Phos¬ 

phorus. 

Sulphur. 

•57 

.22 

.266 

.044 

•63 

•33 

•254 

.040 

.89 

,06 

.287 

.040 

•75 

.66 

.240 

.030 

.72 

.14 

•93 

.026 

•47 

.09 

.190 

.032 

.42 

.07 

.196 

.029 

1.46 

•50 

.092 

.0321 

•59 

•25 

.271 

.048 

.65 

•31 

•237 

.040 

1.69 

47 

.274 

•037 

•75 

.66 

.248 

.030 

2.09 

•43 

.272 

.042 

1.64 

.98 



n.70 

1.00 




Remarks. 


Cast into chill roll (Mr. West) 
Cast into chill roll (Mr.West) 
Cast into dry sand. 

Caat into chill roll (Mr. West) 
Cast into dry sand. 

Cast into dry sand. 

'Cast into dry sand. 

Cast into dry sand. 

No. 48 in sand rolls (Mr. West) 
No. 49 in sand rolls (Mr. West) 
Cast into dry sand. 

No. 51 in sand rolls (Mr. West) 
Cast into green sand. 
Re-melted ferro-silicon No. 
5, cast into chill roll (Mr. 
West). 

Re-melted ferro-silicon No. 
5, cast into sand roll (Mr. 
West). 


“For abetter comparison of the melting points of the 
same irons cast into sand and into chills, as made by 
Mr. West, the following table is subjoined: 

table 80. 


No. 

Combined 

Carbon. 

Graphite. 

Fracture. 

Melting 

Point. 


57 

1.60 

3.16 

Gray 

22IO°F. 


49 

4.67 

•03 

White 

2000 

Same ladle. 

58 

i -57 

2.90 

Gray 

2250 


50 

4.20 

.20 

White 

1990 

Same ladle. 

60 

1.20 

2.90 

Gray 

2250 


52 

3-90 

.16 

White 

2000 

Same ladle. 


TABLE 8l.— ALLOYS AND STEEL. 


d 

Melting 

Point. 

Carbon. 

Silicon. 

Manga¬ 

nese. 

Chro¬ 

mium. 

Tung¬ 

sten. 

Remarks. 

J 64 

2450°F. 

1.18 

.21 

•49 



Steel. 

65 

235 ° 

1.32 

.29 

1.27 

3-40 

6.21 

Steel. 

66 

2280 





39.02 

Ferrotungsten. 

67 

2240 


» . . • • 



11.84 

Ferrotungsten. 

68 

2255 

5.02 

1.65 

81.40 



Ferromanganese. 

69 

2210 

6.48 

.14 

44-59 



Ferromanganese. 

7 ° 

2400 

6.80 



62.70 


Ferrochrom. 

71 

2230 

6.40 



19.20 


Ferrochrom. 

72 

2260 

1.20 



19.10 


Ferrochrom. 

73 

2180 

1.40 

. 

. 

5 - 4 o 


Ferrochrom. 





























































































354 metallurgy of cast iron. 

The tables of the pig and cast irons have been 
arranged according to their combined carbon contents, 
for it is evident that with few exceptions the melting 



FIG. 68.—APPARATUS FOR DETERMINING THE MELTING POINT OF PIG 

IRONS, ETC.— FRONT VIEW. 



















THE MELTING POINT OF CAST IRON. 


355 


points increase as the combined carbon goes down, 
this being the case independent of the amount of 
graphite present. One could hardly expect anything 
else, for that matter, gray cast iron being really a steel 
with a lot of mechanically mixed graphite, and white 
iron a combination of carbon with iron. Alloys melt 
at a lower temperature than any of their constituents, 
and so also white iron — really an alloy of carbon or 
some carbides of iron with iron — should melt sooner 
than the purer iron in the gray variety. 

“The fact, however, that steel melts at a much higher 
temperature than the grayest of irons in the table, 
shows that there are other considerations not to be 
overlooked in studying the molecular physics of cast 
iron. The principal reason for this lowering of tern] 
perature is the supposed solution of the graphite in the 
iron before actual melting takes place. To what 
extent this occurs and under what circumstances is not 
known, but may account for the difference in the 
melting points of steel and gray iron. 

“Again, in melting steel in the cupola commercially, 
an absorption of carbon from the fuel takes place, the 
melting point is doubtless lowered a little, and the 
results obtained are tangible, even though care must 
be taken to get the whole of the charge down before 
pouring. In the air furnace the steel absorbs carbon 
by contact with the pig iron charged and melts off, the 
wasting of wrought iron or steel poking bars used for 
rabbling giving evidence of this occurrence. 

‘ 4 The writer is especially pleased to see the full corrob¬ 
oration of Mr. West’s elaborate experiments with the 
melting of white and gray irons. The contrast is 
remarkably sharp, and on the whole it shows us that 


35 6 


METALLURGY OF CAST IRON. 


science and practice go hand in hand admirably, no mat¬ 
ter what the field maybe. Whatever theories may de¬ 
velop regarding the melting of iron, whatever the effect 
of high or low phosphorus, silicon, manganese, and 
sulphur may be shown to be on the melting point of 
an iron eventually (the present series of irons not 
being well enough adapted for this phase of the ques¬ 
tion), the results here given are, it is hoped, of suffi¬ 
cient value to stimulate further research of practical 
value to the founders of cast iron. ’ ’ 


\ 


1 


CHAPTER XLVJII. 


ALUMINUM ALLOYS IN FOUNDING. 

Aluminum was discovered, it is claimed, by Fred¬ 
erick Wohler, a German professor, in 1827; but to St. 
Clair Deville, a Frenchman, belongs the honor of be¬ 
ing the founder of the aluminum industry. The first 
article made of this metal, it is said, was in compliment 
to Louis Napoleon, the benefactor of Deville, and was 
a baby rattle for the infant Prince Imperial. About 
ten years ago it was thought that aluminum would 
revolutionize all metallurgy, but usage and practical 
tests have more closely defined its sphere. We find 
that to-day its adoption is chiefly limited to the manu¬ 
facture of fancy commercial wares, also alloys of brass 
and bronze, the former being extended to an industry 
employing a large number of wage earners. 

In the first days of the aluminum industry great diffi¬ 
culty was experienced in obtaining perfect castings 
with aluminum alloys. It was seldom that a sound 
casting could be obtained. The Cowles Electric 
vSmelting and Aluminum Co., of Lockport, N. Y., one 
of the first to manufacture aluminum alloys, etc., en¬ 
gaged the author, in the year 1886, to go to Lockport 
for a short time. The author’s experience in this 
foundry resulted in finding aluminum, as an alloy, 
very wild in its actions, and that the greatest difficulty 
might always be expected with it in obtaining strictly 


358 


METALLURGY OF CAST IRON. 


aluminum bronze castings. I have seen a pot of alu¬ 
minum bronze kept for twelve hours in a furnace be¬ 
fore tests had proven it to be the grade of metal de¬ 
sired, and the chances were that, had it proven all 
right, if a second test had been taken a few moments 
later it would have shown that a great change had 
taken place in the metal. The author succeeded in 
obtaining sound castings from some very complex pat¬ 
terns, but he was not able to make any formula or di¬ 
rections for a mixture which would insure like desired 
results every melting, as far as physical tests were 
concerned. It must be remembered that at this time 
pure aluminum was not obtained for commercial pur¬ 
poses, as it is at the present day. Then it was only 
obtainable by being alloyed with iron or copper con¬ 
taining from about 5 to 20 per cent, of aluminum. To 
obtain 5 to 20 per cent, of aluminum in any alloy of cop¬ 
per or iron, 80 to 95 per cent, of these latter elements 
had to be melted in mixture with what was in the pot in 
order to have a chance of securing the grade wanted. 
Since the advent of the Pittsburgh Reduction Co., 
about the year 1890, aluminum is obtainable for com¬ 
mercial purposes in a free state, without being alloyed 
with any other metal. This has proved more satis¬ 
factory in enabling a formula to be utilized to the end 
of securing like results at all times, but has not re¬ 
moved the difficulty of obtaining perfect castings of 
aluminum bronze alloys. 

The author has tried aluminum in mixture with cast 
iron. In some cases it would slightly improve the 
strength, and again it would weaken the iron. The 
influence of aluminum is similar to that of silicon. 
Where the combined carbon is high, it will lower it so 


ALUMINUM ALLOYS IN FOUNDING. 


359 


as to make the iron of a softer nature. Where the 
graphite is highest, it will close the grain and give the 
iron a leaden color and generally decrease its strength; 
whereas the reverse will generally be true if the com¬ 
bined carbon has overreached that point which would 
afford the iron the greatest strength. On a whole, 
aluminum, as far as strength is concerned, is only of 
value in use with very hard grades of iron, or those 
exceeding 1.65 in combined carbon. The percentage 
of aluminum which I used would range from one-quar¬ 
ter of one per cent, to 1^ per cent. The aluminum 
was placed in the bottom of the ladle and the molten 
metal poured over it. I found this plan better than 
throwing it into the molten metal after the ladle had 
been filled. In both cases the metal would always be 
stirred with a rod to assist in mixing the metals. 
Aluminum will increase the fluidity of molten metal, 
but to obtain the best results in this line it must be 
used with care and judgment. To secure the greatest 
fluidity by means of aluminum depends upon the per¬ 
centages of the elements which compose the iron de¬ 
signed to make it soft or hard. The harder the iron 
the more aluminum can be used to obtain the greatest 
degree of fluidity. With soft grades aluminum can 
make the metal sluggish, with excessive dross on its 
surface, just as can be the case by having too much 
silicon in a mixture. 

While the way in which aluminum will generally 
work in affecting the different percentages of carbon 
in iron are above outlined, still, on the whole, it is 
very erratic and will often act contrary to expectations. 
One peculiarity about aluminum alloyed with iron is 
displayed where two ladles are used to pour a mould, 


3 6 ° 


METALLURGY OF CAST IRON. 


often showing a “cold shut ” or bad union of iron at 
the point where the streams of metal from the respect¬ 
ive ladles meet each other. Aluminum is also alloyed 
with silver, nickel, tungsten, manganese and silicon, 
as well as copper, iron and steel. 

Pure aluminum is the lightest of all known metals, 
except magnesium. Its specific gravity is from 2.6 to 
2.7 and it melts at about 1215 degrees F. It is white 
in color, of a soft nature, possessing a strength of about 
one-third that of wrought iron. While pure aluminum 
melts at 1215 degrees F., still its reduction in the blast 
furnace from any ore is such as not to alloy with the 
iron to any extent. In all the author’s experience 
with aluminum in cast iron he cannot say that he ever 
knew it to accomplish anything which could not be 
obtained by means of silicon, which is much cheaper 
than aluminum. 

* For the specific gravity and weight per cubic inch of other 
metals, see Table 136, page 593. 



PART III. 


CHAPTER XLIX. 


METHODS FOR MELTING CAST IRON TO 
TEST ITS PHYSICAL QUALITIES. 

Owing to the impracticability of judging pig metal 
by its fracture, the author has thought a Chapter on 
methods for melting small quantities to test its phys¬ 
ical qualities would, in many cases, prove of value, es¬ 
pecially where a founder was not in position to utilize 
chemistry. 

There are three methods by which iron can be 
melted for testing its physical properties. One is to 
take the regular “ heats ” mixture, another to have a 
very small cupola expressly for melting light “heats,” 
weighing from 50 to 500 pounds, and the third by 
means of a furnace and crucible similar to the prin¬ 
ciple used for melting brass, etc. By using metal 
from the first, we can at any period of a heat tell the 
physical properties of any mixture poured at that time. 
By using the small cupola we can, by proportioning a 
mixture in light charges, obtain a good approximate 
knowledge of the product to result from a like mixt¬ 
ure in regular “heats,” and also where there are sev¬ 
eral brands or grades of pig metal, each can be tested 
separately, to ascertain its physical properties, thus 
enabling one to detect any brands that might be de¬ 
ceptive in appearance and thereby contaminate and 


METHODS FOR MELTING TO TEST CAST IRON. 


prevent physical results being* obtained from any 
desired mixture. By melting in the crucible, we can 
closely tell the physical properties in respect to what 
the chemical elements would define it in the original 
state, when not affected by the sulphur, etc., in fuel, 
but not what it would be when remelted. Why this 
is so involves elements most essential for the founder 
to understand and are treated further in Chapter 
XLV. 

Melting a mixture in a crucible with the expectation 
of obtaining tests to denote what the physical qualities 
of a regular cupola mixture would be, is impractical. 
These can be told with fairness by taking tests from 
the regular cupola. Small cupolas ranging from fifteen 
to twenty inches inside diameter can often be well 
used to test single brands or grades or mixtures not 
having over four different kinds of iron. As there are 
cases where some would like to use a small cupola 
for crucible melting also, I have studied to the point 
of combining the two, and as a result present the fol¬ 
lowing original device or small cupola, as seen in Fig. 
69, next page. This cupola can be erected in any out- 
of-the-way place, or by the side of a regular “ heat ” 
cupola, so that the flue A can be attached to head off 
the sparks, etc., when used as a cupola, without risk of 
setting anything on fire, should there be any danger 
of this; if not, then the cover B could be dispensed 
with and the flame, etc., permitted to pass out at the 
top. B is a cover made of cast iron, and having prick¬ 
ers on the under side for the purpose of holding a daub¬ 
ing of clay to prevent the heat of the furnace burning 
the cover. The handle D is for convenience in lifting 
the cover on and off when desiring to change or take 


364 


METALLURGY OF CAST IRON. 


t < 


out a crucible. The staging H as shown is placed any 
height to suit the operator. The cupola has four 
tuyeres, two inches in diameter. In charging to run a 
heat,” have the coke ten inches above the tuyeres; 

d if coal, seven inch- 

e s ab ove the 
^ tuyeres. The fuel 
should not be 
much larger than 
double egg size, 
and the bed well 
burned up before 
the first iron is 
charged. On the 
bed, place fifty to 
one hundred 
pounds of iron, 
which, if pig iron, 
should be broken 
in lengths of from 
five to eight inch¬ 
es. If the pigs 
were too strong to 
break by sledg¬ 
ing, etc., one-inch 
holes could be 
drilled 


and a 
,punch used to 
fig. 69.—west’s combined cupola and fracture. Should 

CRUCIBLE FURNACE. , 

more than 100 

pounds require melting, charge twenty pounds of coke 
or coal, and on this one hundred pounds of iron, and so 
continue as long as the cupola works all right. With a 



































































































methods for melting to test cast iron. 


slag-hole as at E, Fig. 69, and the use of flux, a “ heat ’ ’ 
can be prolonged to run several hours. If lime was 
used for a flux, about four pounds to every one hun¬ 
dred of iron charged should cause the slag to run freely. 
We are only entering into these details in order to illus¬ 
trate the fact that the cupolas can be used for heavier 
“heats” than test bars would necessitate.* 

In melting with a crucible in the cupola, Fig. 69, 
use a size like No. 18 Dixon’s brass. In preparing 
the cupola for melting with crucibles, put in a sand 
bottom within two inches of the level of the tuyeres. 
Have a bed of coke, when well burnt up, ten inches 
high, and on this set the crucible charged with its 
burden of iron to be melted. Fill all around between 
the crucible and the cupola lining with small coke, 
level with the top of pot. Cover the pot over with a 
clay cover, which can be formed in a core box and 
rodded the same as one would a dry sand core to pre¬ 
vent its cracking, or the bottom of an old crucible can 
be used. The smaller the iron is broken the more 
quickly it will melt, and hence the easier will it be on 
the pot and more economical in fuel. After the pot is 
covered, the cover D is placed on to close the furnace. 
The blast is now put on the same as if iron were being 
melted direct in a cupola. The pressure should, for 
crucible work, range from two to three ounces; for cu¬ 
pola work, four to eight ounces can be used, and such 

* Should any desire plans, with complete specifications, for con¬ 
structing small, permanent cupolas, ranging from twelve inches 
to eighteen inches diameter, strictly for melting light “heats” 
without crucible arrangements, we would refer them to “Moulder’s 
Text-Book,” page 265, and in the same work, page 248, will be 
found a cheap temporary arrangement for melting from fifty to 
one hundred pounds of iron. 



366 


METALLURGY OF CAST IRON. 


blast can often be supplied from a blacksmith’s forge 
fan. Should it be desirable to run steadily all day for 
crucible work, the breast should be dug out about 
twice during the “heat,” and the ash and dross pulled 
out, so as to leave room for clean fuel. In making the 
breast for crucible work, have it formed of a sand that 
will not bake or cake hard and larger than shown. 
This will permit its being dug out readily. 

Should it not be desired to use the device as a combina¬ 
tion furnace and cupola, but strictly for crucible work, 
we would advise sinking the same in a pit, and in¬ 
stead of using the regular cupola drop bottom, which 
goes with this device, have the bottom consist of a reg¬ 
ular grate, with an ash pit six inches deep, the diam¬ 
eter of the grate. Have the ash pit closed air-tight, 
and instead of admitting the blast into the body of the 
furnace, as is done with the cupola here shown, let it 
pass into the ash pit and enter the furnace through 
the grates. By having a pit three feet by five feet and 
three feet deep the combination cupola and furnace 
could be lowered to bring the staging line H level 
with the floor. This would make it more convenient 
for charging, or lifting a crucible in or out, and by 
having a handy step-ladder, ready access can be had to 
the pit for “tapping out” or cleaning the “ dump.” 
For raising a pot of metal up to the floor, employ a 
pair of tongs similar to those used for lifting a crucible 
out. The flue A should be lined with fire brick or clay 
for any distance the outer shell could be heated red 
hot were it not lined. This flue should be well bound 
with stays to prevent the heat cracking it open. 

As very few founders have had opportunity for ex¬ 
perience in crucible work, we will detail more points 


METHODS FOR MELTING TO TEST CAST IRON. 367 

necessary to be followed. As melting 1 progresses, the 
fuel around the sides of the pot will settle down. 
This must be replenished so as to keep the fuel about 
on the level with the top of the pot. To have it high¬ 
er at the first would be an advantage. Judgment 
should be used not to fill in fuel when the pot is about 
ready to be pulled out, as this will tend to cool the 
metal and prevent the free use of the tongs in grasp¬ 
ing the pot to remove it from the furnace. A pot will 
settle more or less in the fuel and it may be necessary 
to lift it up several times .so that the fuel from around 
the sides can settle down and raise the pot, after which 
the sides, of course, would require fresh fuel. In 
charging the iron, the pot may not hold all that is de¬ 
sired at the first filling. In such case, additional iron 
can be charged as fast as the solid melts down. The 
crucible will average about forty heats, if handled care¬ 
fully. The least moisture in a pot would cause it to 
crack in the fire. It must be thoroughly dry before 
being used for a “heat.” A good practice is to place 
a crucible in an oven for several days before using it. 
While it is essential to have the moisture all out of the 
pot, it is also well to never permit it to cool off sud¬ 
denly. If after a heat the pot is set back in the fire to 
cool down with it, its life will be prolonged. Iron 
melted in a crucible will be found to possess a quiet 
appearance, and it is generally not so hot as coming 
from a cupola. In operating either the cupola or the 
crucible, only the best of fuel should be used, and all 
work should be intelligently manipulated. 


CHAPTER L. 


JUDGING OF AND TESTING MOLTEN 

IRON. 

In testing iron we have two properties, chemical and 
physical, to which we might add the phenomenon of 
fusion. An experienced eye can often very fairly tell 
what a casting will be, physically, by judging the 
appearance of the metal when running or at rest in a 
ladle. 

In many cases the ability to judge liquid metal 
will often prove of value, for while we seldom have 
means for changing its character when fluid, we can 
often refrain from pouring work when our judgment 
asserts that a metal is radically wrong. There is 
this much that can be said of re-melted fluid iron: It 
will rarely, if ever, deceive an expert, as can the judg¬ 
ing of iron in the pig before being melted. We can 
rest assured that if it looks radically soft in a liquid 
state, it will not prove hard in a solid one, and vice 
versa. 

The ordinary moulder can, with a short experience, 
tell the degree of fluidity, or whether the iron is 

hot ” or “ dull. ’ ’ Why he should be better able to 
do this than judge of its physical qualities when mol¬ 
ten, is mainly due to present practice not often afford¬ 
ing means to change or correct a metal that might not 
look right. The degree of the temperature before 


JUDGING OF AND TESTING MOLTEN IRON. 369 

being poured he can often greatly control, and hence 
the advantage of practice in this factor causes study to 
train the eye, which very soon becomes expert in de¬ 
ciding the best moment at which to pour a mould. A 
like study of the molten character, combined with the 
temperature in a fluid state, may enable the moulder 
to judge as well in one case as the other, and this 
should be practiced more than it is, as no moulder or' 
founder can tell when a knowledge of the former 
would not be as valuable as the latter. 

Judging the grade of metal by>its appearance in a 
fluid state is often done by experienced founders, and 
with a little study and observation the following de¬ 
scription may often enable the inexperienced to soon 
become proficient in judging molten metal: A No. i 
or high graphite soft iron * will generally present a 
lively vibration of different colors having the appear¬ 
ance of coming up from below the surface, forming an 
oxidized crust. This crust has the appearance of strug¬ 
gling to break away from alloys, which do not take 
kindly to being associated with a grey or soft iron. 
When No. i iron is slowly cooling down from a high 
temperature to a low one, it will often be unable to 
hold all its carbon in a combined state. What cannot 
be retained will gradually rise to the surface as graph¬ 
ite in the form of a scum or kish, and in the latter 
state will float away in the air, often covering every¬ 
thing near at hand with thin flakes of shining mate¬ 
rial, looking like silver lead or plumbago. This can 
properly be called pure carbon freed from the metal. 
About blast furnaces, this latter phenomenon can 
often be seen, sometimes so active that the employes 
will be covered with “kish,” making them look 

*This refers to iron possessing from 2.50 to 3.00 of silicon. 
For results of higher silicon, see next paragraph. 



3 7o 


METALLURGY OF CAST IRON. 


like a fishmonger covered with shining fish scales. 

When metal is high in silicon, its surface may have 
a smooth, dead appearance devoid of life, and if 
the surface is disturbed with a rod or skimmer, it may 
act a great deal like cream upon milk. Were it 
not for its dull, silvery, quiet appearance and spark¬ 
less action, it might often be taken for hard iron. 
No. i iron, whether high in free carbon or silicon, 
when running from the cupola into a ladle or from 
the furnace to the pig beds, throws off very few 
sparks, and those that do fly are chiefly caused b)^ vi¬ 
bration of the metal from the running or spluttering 
of the stream, and fall as ordinary sparks, very differ¬ 
ent from those which come from harder or lower 
grades of melted iron. 

Irons low in silicon and high in sulphur, from No. 7 
to No. 10, which can be termed hard iron and' also can 
be strong and weak, have peculiarities very' pro¬ 
nounced to distinguish them from soft grades or No. 1 
irons. In the ladle, such irons will, when “hot,” 
show a smooth, bright appearance, with hardly a break 
on the surface, and as the mass becomes cool or “dulls 
down,” it presents a dull, hazy, plastic appearance, 
which, if disturbed by a skimmer or rod, will act as if 
it were covered with an oxide or scum. While hot, it 
will often boil in the ladle as if bubbles of gas were 
escaping from below. It also emits many sparks, 
which is the chief characteristic phenomenon of hard 
iron and cannot be better explained than in the lan¬ 
guage of Tomlinson, who says: 

From all parts of the fluid surface is thrown off a vast number 
of metallic sparks, from the absence of carbon, which renders the 
metal sensitive to the oxidizing influence of the atmospheric air. 


JUDGING OF AND TESTING MOLTEN IRON. 


371 


Small spherules of iron are ejected from all parts of the surface 
to the height of five or six feet, and sometimes higher, when they 
inflame and separate with a slight hissing noise or explosion into 
a great many particles of brilliant fire, forming oxide of iron. 

The blast furnaceman can often tell very closely the 
‘ ‘ grade ’ ’ an iron will show by analysis when cold, by 
its appearance when fluid, and whatever practical 
methods a founder can utilize will, at some time or 
other, prove very beneficial, especially in “ air fur¬ 
nace ” workings and long “ heats ” in cupolas, for with 
the latter there is a chance given, if at the first 
tappings iron proves itself radically wrong, through 
any errors in figuring analyses, or in charging the 
iron, etc., to alter the charges in order to change the 
“ grade ’ ’ of the metal before a heat is finished. 


CHAPTER LI. 


RESULTS OF VARIATION IN THE FLUID¬ 
ITY OF METAL AFFECTING 
PHYSICAL TESTS. 

Variation in the fluidity of molten metal is a fac¬ 
tor which the author has discovered to be very impor¬ 
tant to note in considering the depth of an iron’s chill, 
taken by means of a test bar or “ chill block.” It is 
a point which does away with past records or statistics 
which have been compiled by some from deduc¬ 
tions taken from the depth of a chill, by the pro¬ 
nounced manner in which it asserts itself in giving 
evidence of being affected by the degree of fluidity at 
which a test bar is poured. In experiments with iron 
poured “ hot ” and “ dull,” the author has made the 
thickness of chill as great again in one case as in the 
other. Take, for instance, two test bars and pour one 
hot so that the iron will run up in the fluidity strips 
described in Chapter LXVI., page 509, about six inches 
high, and then cool the iron so as it will only run up 
about an inch: it will be found upon breaking the bars 
to test the chill that the hot-poured bar will have 
chilled about as much again as the dull-poured one. 
I have not accepted this principle as a fact from a test 
or two, but have made many to fully assure myself 
that the principle is correct. 


RESULTS OF VARIATION IN FLUIDITY OF METAL. 373 


The Tables seen on page 376 show the difference 
in chill by reason of “ hot ” and “ dull ” poured iron, 
in test bars i}& inch diameter cast on end. It will be 
noticed that the fluidity of the hottest poured bar in 
Table 82 was but four inches, and the dullest one, one 
inch, a difference of three inches, but this was suffi¬ 
cient to make a difference in the chill of five-sixty- 
fourths of an inch, and this was the same iron poured 
out of the same ladle. A chemical analysis of the 
iron charged in the cupola and that obtained in the 

test bars is also given 
in Table 82. In Fig. 
70, K shows the fract¬ 
ure of the hot-poured 
bar, and P the fracture 
of the dull-poured one, 
from which a good 
realization can be re¬ 
ceived of the effects 
different degrees of flu¬ 
idity can cause in giv¬ 
ing different depths of 
chill from the same iron poured from the same 
ladle and which is forcibly shown by the Tables, 
page 376. 

In the Table we find a difference of .078 inch in the 
chill of the two ^-inch bars which were poured out of 
the same hand ladle holding about fifteen pounds of 
metal. The first bar was poured as soon as the metal 
was carried to the “ floor,” and the second bar three 
minutes later. Here we find there is a difference in 
chill of .078, due to difference in fluidity of metal, or 
in rough figures fa inch, as seen at V and S, Fig. 70. 



Dull Iron Hot Iron 

Chill Chill 

FIG. 70. 








374 


METALLUkGY OF CAST IRON. 


I state the time between the pourings to give an idea 
of how long the metal was held. 

The fluidity strips are the practical guide to go by. 
Of what use is time in regulating or asserting the 
fluidity of irons between two foundries, or one heat 
from another? The iron in no two foundries is of the 
same fluidity, or for that matter the same foundry will 
seldom have two days’ run in succession alike, and 
where one shop could only hold its metal for five min¬ 
utes, another might do so for ten. There is no guide 
to register the fluidity of molten metal better than 
fluidity strips attached to test bars, as advocated by 
the author in Chapter LXVII. For scientific re¬ 
search and close regulating of mixtures by physi¬ 
cal tests, it is essential for fluidity strips to be at¬ 
tached to test bars, where one desires to obtain true 
knowledge of irons or mixtures. I have shown that 
degrees in fluidity affect the depth of chill, also that it 
is incorrect for a test bar to pull away from its chill 
when contracting, as seen in Chapter LVI. This lat¬ 
ter evil only aggravates more the one caused by 
different degrees in fluidity, as both elements are 
effective in causing erratic depths of chill. 

I could have shown a much more radical difference 
in the chill obtained from the same ladle by different 
degrees of fluidity, and would here say that in one 
case I found with the same iron in pouring two -inch 
bars that the dull-poured one had a chill of ^ inch, 
the hot-poured one y inch, a difference of T 3 g inch. 

For any that desire to test the question of degrees 
of fluidity causing different thicknesses in chill, in 
inch square test bars, I have presented the plan I used 
in my experimenting with a >4-inch square test bar. 


RESULTS OF VARIATION IN FLUIDITY OF METAL. 3 75 


k- 

1 { Knife Edge 


10 - 


gj thick I 

---7T-^- 


T 

I . 


which is seen below at Fig. 71. In using this device 
to get two test bars, I moulded two separate patterns, 
in a flask large enough to admit them and hav¬ 
ing four inches of space between them, so that 
the gas or heat from the first poured one could not 
affect the other bar. The flasks were leveled so as 
to afford like conditions for the running of the met¬ 
al into the fluidity strips. For chills at the ends of the 
test bars I used pieces of ^-inch square wrought iron 
rods, cut to a length of two inches, and loosely set 

them against the 
ends of the pat¬ 
tern when mould¬ 
ing. Should any 
one desire to cast 
two bars at the 
same time in one 
flask, they would 
require, of course, but one gate, and it in the mid¬ 
dle, leaving the fluidity strips on the outside of each 
bar. Fluidity-measuring testing tips, cast on test bars, 
are an entirely new departure originated by the author, 
and found by him to be of much value when very close 
records are desired for comparisons of chill records, 
etc. The plan devised for using fluidity strips with 
test bars cast on end is described and illustrated in 
Figs: 121, 122, pages 509 and 514. 


b 

IB — 




- n 

% thick 


Touring f ) Gate "Y<S 

Ha If inch square Test Bar 13 long 


fig. 71 . 















■j(y METALLURGY OF CAST IRON. 

TABLE 82 .— PHYSICAL TEST TAKEN WITH I-INCH ROUND BARS. 


Micrometer Measurement. 


No. of Test. 

Fluidity. ' 

Shrinkage. 

Contraction. 

Deflection. 

Strength, 

broke in 

lbs. 

1 

Chill. 

Diameter of 

test bar. 

Strength per 

sq.inch in 

lbs. 

1 

2 

4 " 

1" 

30 

16 

.156" 

.156" 

. 120" 
.110" 

L 505 

L 5 °° 

.172" 

.094" 

1.130" 
1.117" 

1.501 

L 53 i 


Common Measurement. 


1 

4" 

30 

10-64" 

7 - r 4 " 

1,505 

11-64" 

1 8-64" 

2 

1" 

l6 

10 64" 

6-64" 

1,500 

6-64" 

1 7-64" 


Analysis of Pig Iron Charged. 


Analysis of Test Bars. 

Silicon. 

1.46 

Sulphur. 

•039 


Silicon. 

1.26 

Sulphur. 

.072 


PHYSICAL TEST TAKEN WITH HALF-INCH SQUARE BARS. 


No. of Test. 

Fluidity. 

Deflection. 

Strength in 
lbs. 

Chill. 

1 

11/," 

. 190" 

300 

.048 

2 

8" 

. 190" 

290 

• c8o 


Analysis of Pi 

g Iron Charged. 

7— - 1 

Analysis of Test Bars. 

Silicon. 

Sulphur. 

Silicon. 

Sulphur. 

1.82 

•°35 

1.67 

.056 
































































CHAPTER LII. 


SPECIFIC GRAVITY OF VERTICAL- 
POURED CASTINGS. 

Below is given an extract from a paper by the au¬ 
thor, read before the autumn meeting of the Iron and 
Steel Institute, at Birmingham* England, August 20- 
23, 1895: 

Some authorities have asserted that a test bar cast 
on end, if placed on supports equidistant from either 
end, would not break at the point where the load is 
applied, but at a point an inch or so away from the 
point of pressure toward the uppermost cast end of the 
bar. In a long experience with bars cast on end, the 
author has failed to find any such condition. Indeed, 
he has not found any difference in this respect with 
bars that were cast flat or on end. With a view to 
thoroughly investigating the matter, he conducted the 
following experiment, and obtained the information 
given by the Builders’ Iron Foundry of Providence, 
R. I., cited, and shown in Table 84, page 379. These 
are tests which the author first presented in a discus¬ 
sion on testing at the meeting of the American Society 
of Mechanical Engineers, held in New York City on 
December 3, 1894, and later gave them in a paper be¬ 
fore the Iron and Steel Institute. In the first test of 
specific gravity, he wished to call attention to the fact 
that the specimen used was strictly a parallel gate test 


3 7 8 


METALLURGY OF CAST IRON. 


bar. He mentions this fact for the reason that in the 
discussion above cited, one member of the American 
Society took the position that the specific tests on page 
379 were inadmissible proofs to establish any prin¬ 
ciple, owing to the bottom end of the gun which was 
cast down being of a more massive nature than the up¬ 
per end, and hence there was good reason to expect 
metal to be less dense in the bottom than in the upper 
end of the gun. The following test of the parallel 
gate which the author conducted shows the fallacy of 
the idea that the lower end of vertical-poured castings 
must be of a greater specific gravity than the upper 
end. In the experiment which the author conducted 
at his own foundry, he took a “ gate ”6^ feet long and 
3 inches in diameter, which had been used for pouring 
an iron ingot mould casting, and took a test-piece 6 
inches from the top, and another 5 feet from the top. 
The gate was practically parallel, so that, in turning 
these specimens in the lathe, the same amount of sur¬ 
face was carefully removed from each. The speci¬ 
mens were machined of exact size, and were then de¬ 
livered to the laboratory of the Case School of Applied 
Science, of Cleveland, O., to be weighed. The deter¬ 
minations (Table 83 ) reported by Prof. C. H. Ben¬ 
jamin were as follows: 

TABLE 83. 

Weight of top end of gate in vacuum.1169.468 grammes. 

Weight of bottom end of gate in vacuum.1167.239 “ 

Volume of top end of gate. 165.722 cubic centimetres. 

Volume of bottom end of gate... 165.768 “ “ 


1169.468 

Density of top end of gate. ... 7.0568. 

165.722 
1167.239 

Density of bottom end of gate.... 7.0414. 

165.768 

DifFerence=o.oi54 only. The plug from the upper end is the denser. 










SPECIFIC GRAVITY OF VERTICAL-POURED CASTINGS. 379 


Table 84 presents a series of tests on the specific 
gravity of vertical-poured gun castings. 


TABLE 84. —TESTS OF SPECIFIC GRAVITY OF FIRST AND LAST SIX 

MORTAR CASTINGS. 



Specific gravity of 

Specific gravity of 

Number of Heat. 

muzzle or top end 

breech or b it tom 


of gun. 

end of gun. 

78 . 

7.238 

7.2478 


7.2436 

7-2447 

80. 

7.256 

7.269 


7-2934 

7.2882 

88... 

7.278 

7-285 

89.. 

7-335 

7 329 

185. 

7.3263 

7.3182 


7-3325 

7-3252 

187. 

7-3404 

7-345 

188. 

7-3636 

7-3336 

189. 

7-349 

7-340 


7-3345 

7.3267 

Total. 

87.6903 

87 6524 

Average. 

7-3075 

7-3043 


The lower test disc was taken about 11 feet from the 
top of the casting and the upper test 2^2 feet from its 
upper end. The majority of the tests showed the 
specific gravity of the muzzle specimens to be higher 
than the breech specimens and also to be harder and 
of higher tensile strength. This is the reverse of 
what many would expect. Table 84 shows the average 
specific gravity of all the casts made for specific gravity 
of breech and muzzle specimens on the first six mortar 
castings and on the last six mortar castings made by 
the Builders’ Iron Foundry, from whom the author 
received these tests, and wishes here to tender his 
thanks for the kindness rendered. 

The tests and figures in Tables 83 and 84 indicate 
that there is no condition which will cause any prac¬ 
tical difference in the lower and upper end of long 




























3 8 ° 


METALLURGY OF CAST IRON. 


vertically-poured castings, in the sense which has been 
generally accepted. 

In considering the gun and gate tests of specific 
gravity in connection with those referring to the 
density of the lower side of flat-cast test bars being 
greater than the top side, discussed in Chapter LXV., 
it would at first seem as if the results were contra¬ 
dictory as far as they relate to the enunciation of 
any law or principle governing the quality of specific 
gravity in vertical-poured casting. The gate and gun 
tests show the upper end to have the greater specific 
gravity, and that of flat poured test bars to have the 
greater density in the side cast downwards. The 
latter is largely due to the bottom portion or sur¬ 
face of flat-cast test bars being most affected by 
the chilling qualities of the sand of the mould when 
it is filled with molten metal. If the specific grav¬ 
ity had been taken from the bottom surface of the 
gate test bar and gun castings, instead of a few 
inches in height from their bottom end, as was done, 
there might have been a difference found in favor of 
the lower end being the denser. This is, however, 
doubtful, as the gun and gate specimens had such a 
small area exposed to the mould’s cooling influence, 
compared to the mass of metal comprising the castings. 
On the other hand, with test bars cast flat, the reverse 
occurred, and this is due to the fact that a fair per¬ 
centage of the metal comprising the test bars is dis¬ 
tributed over a large area of mould surface and is 
affected by the cooling qualities of damp sand, which 
is an unnatural effect that cannot be charged to spe¬ 
cific gravity proper. 

When the specific gravities of long vertical-poured 


SPECIFIC GRAVITY OF VERTICAL-POURED CASTINGS. 381 

castings are tested a few inches from the bottom and 
a few inches from the top, the reason for finding the 
upper end the denser, as exhibited by the tests record¬ 
ed, the author defines as being largely due to the law 
of metal expanding at the moment of solidification. 
Expansion tending to make the upper end of castings 
as dense as the lower may be better understood when 
it is stated that molten metal begins to solidify at the 
bottom of a mould and rises in height as the solidifica¬ 
tion continues. The effect of expansion at the mo¬ 
ment of solidification, as castings “ freeze ” from the 
bottom upwards, has a crowding action, tending to 
make the molecules denser as solidification increases, 
thereby partly neutralizing the effect in the difference 
of the specific gravity naturally expected to exist while 
the metal is in a fluid state. The author has obtained 
the following Table 85 of analyses of the top and bot¬ 
tom piece of the vertical-poured parallel gate test bar 
from E. D. Estrada, M. E., of Pittsburgh, Pa.: 


TABLE 85. 



Carbon. 

Phosphorus. 

Manganese. 

Silicon. 

Sulphur. 

Top piece. 

3-72 

0.091 

0.31 

1.32 

0.046 

Bottom piece... 

3 - 8 x 

0 085 

o -33 

1.32 

0.047 


These results show that practically there is little 
difference in any chemical constituent that might tend 
to equalize the specific gravity of the two ends of the 
vertical-poured parallel gate test bar, and that we are 
left to accept the author’s theory of such results being 
due to the principles involved in the rate of cooling 
and by expansion at the moment of solidification. 


















CHAPTER LIII. 


EXPANSION OF IRON AT THE MOMENT 
OF SOLIDIFICATION. 

The question of iron expanding at the moment of 
solidification was, up to about the year 1897, affirmed 
by some and questioned by others. It remained for 
Mr. John R. Whitney, of Philadelphia, Pa., to first 
demonstrate in a practical way that iron truly ex¬ 
panded at the moment of solidification. This was 
fully verified by the author in experiments which he 
conducted immediately after Mr. Whitney published 
his results in the National Car and Locomotive Builder 
of May, 1889, of which the following is an extract, 
and by later experi¬ 
ments shown on 
pages 384, 387 and 
424: 

On a more recent occa¬ 
sion the following exper¬ 
iment was made with an 
apparatus more carefully 
prepared, as shown, Fig. 72.' A pattern, A, 4 feet long, 3^ inches 
deep and 2^ inches wide, was moulded in open sand; one end of 
the mould being closed by fire brick B, and the other end by a 
piece of gas carbon D, which was suitably connected with a small 
battery and galvanometer. The fire brick B rested at one end 
against a block of iron C, weighing about half a ton. The gas 
carbon block D was carefully secured in the sand, so that the 












expansion of iron, etc. 


3S3 

weight of iron in the mould should not be sufficient to move it. 
The stand K, bearing an arm J, on which the pointer I was deli¬ 
cately pivoted, was then adjusted so that the needle F should 
press against the gas carbon D, and the pointer stand at zero on 
the scale. The long arm of the pointer was 24 inches, and the 
short one 6 inches long, or as 1 to 4. The scale was graduated 
to 1-16 inch. 

A, casting; B, fire brick; C, weight; D, gas carbon block; K : 
stand; I, pointer; J, supporting arm; F, adjusting needle. 

The mould was filled with very fluid hot iron in 17 seconds, 
and then the following results were carefully noted: 

For more than 1 minute after the mould was filled, pointer 
stood at zero. 

At 1 minute 30 seconds after the mould was filled it moved 1-16. 

At 1 minute 50 seconds after the mould was filled had moved %. 

At 3 minutes 10 seconds after the mould was filled had moved #. 

At 5 minutes 20 seconds after mould was filled had moved y. 

At 8 minutes 5 seconds after the mould was filled had moved 
7-16. 

At 11 minutes 30 seconds after the mould was filled had moved 

15 - 32 . 

At 12 minutes 5 seconds after the mould was filled had moved )£. 

From that time the pointer stood perfectly still at y z inch until 
25 minutes 15 seconds after the mould was filled, when the gal¬ 
vanometer showed that contact with the gas carbon was broken 
and contraction had begun. 

I have made several other equally convincing experiments, but 
the length of this article forbids that they should be repeated 
here. 

Long before these experiments were instituted the fact that 
iron follows essentially the same law as water in solidifying was 
well known and published. I need cite only two authorities: 
Prof. Edward Turner, in his “Elements of Chemistry, ’’published 
in Philadelphia in 1S35, by Desilver, Thomas & Co., says, page 
20: “Water is not the only liquid which expands under the reduc¬ 
tion of temperature, as the same effect has been observed in a 
few others which assume a highly crystalline structure in becom¬ 
ing solid; fused iron, antimony, zinc and bismuth are examples 
of it.’’ Prof. Thomas Graham, also, in his “ Elements of Chem- 


3^4 


METALLURGY OF CAST IRON. 


istry, ” published in Philadelphia in 1843, by Lee & Blanchard, 
says, page 385: “ Iron expands in becoming solid, and therefore 
takes the impression of a mould with exactness.” 

As the observation of this law was the basis upon which 
my experiments leading to the successful development of the 
contracting chill for cast iron car wheels was based, I am per¬ 
suaded it will lead to many other practical results of great impor¬ 
tance. This is my apology for trespassing upon your space and 
calling special attention to the matter. 

The illustration 
seen in Fig. 73 is 
one the author dis- 
played in the 
A meric an Machin¬ 
ist , November 1, 

1894, to prove that 
the practice of 
casting bars be¬ 
tween iron yokes, 
etc., prevented 
free action of the 
metal in expand¬ 
ing. 

A one-half-inch 
square test bar, 
twelve inches 
long, was used for an illustration. The author has tried 
by this device one-half-inch test bars without “ gates,” 
pouring them in “open sand ” or without a cope, and 
cannot say he found much difference in their expansion. 
If any difference, the one with the gate showed the 
more. H is an iron block fitting tightly against the 
closed end of the flask. B is an iron block fitted 
loosely into a hole in the open end of the flask, as 


































EXPANSION OF IRON, ETC. 


3 8 5 


shown. D is an arm of which there are two, one be¬ 
ing attached to each side of the flask through which 
the pin A is inserted to give a fulcrum for the indica¬ 
tor arm E to revolve on as the one-half-inch square 
bar expands. 

The length of the lever E is seventy-two inches at 
the long end and the short end should read one and 
one-quarter inches instead of two inches, as shown. 
The dotted line of the indicator shows what the arm 
moves at the time of expansion. It measures about 
one-half an inch, sometimes going over this mark, 
and sometimes a little under it, thus disproving the 
logic that small bodies or test bars will not expand, as 
claimed by some. It makes no difference how large 
or small a body is, the same law is effective in all 
cases of metal cooling from a liquid to a solid body. 

By referring to Chapters LIV. and LV., pages 398 
and 424, two other devices originated by the author for 
recording expansion can also be seen. These devices 
present expansion tests which show the reason for 
there being no practical difference in the specific 
gravity of the two ends of vertical-poured castings, as 
can be seen in Chapter LII., page 381. Then again, 
by referring to Chapter LIV., page 392, the effects of 
expansion in causing shrink holes in castings are fully 
outlined. 


CHAPTER LIV. 


THE EFFECT OF EXPANSION ON SHRINK¬ 
AGE AND CONTRACTION IN 
IRON CASTINGS.* 

The fact that iron expands, when heated, until fusion 
takes place, and that molten iron occupies more space 
than cold, solid iron of the same grade, is now uni¬ 
versally admitted. It was proved by the extensive 
experiments of Mr. Thomas Wrightson, reported in 
the first volume of the Journal of the Iron and Steel 
Institute (1890 and 1891 ), and, in a manner, is illus¬ 
trated in heavy founding by the shrinkage of the mol¬ 
ten metal, which must be “ fed” in order to obtain 
solid castings. 

This decrease in volume requiring “ feeding ” while 
the metal is still liquid I call “ shrinkage ” (see pages 
394 and 395), applying the term “ contraction ” to the 
decrease in volume which takes place after solidifica¬ 
tion, while the iron is cooling to atmospheric temper¬ 
ature. The light-work founder, not having the oppor- 
. tunity to make heavy castings, in which shrinkage can 
be observed, is apt to confound the two; but they are 
in fact distinct, and are separated by an act of expan¬ 
sion, which takes place at the moment of solidification. 


*(Contribution by the author to the Discussion of the Physics of 
Cast Iron, at the Pittsburgh Meeting, February, 1896.) 



EFFECT OF EXPANSION ON SHRINKAGE, ETC. 387 

The fact of this expansion was first practically demon¬ 
strated by Mr. John R. Whitney, of Philadelphia, Pa., 
whose experiments are recorded in the National Car 
and Locomotive Builder of May, 1889, and cited in 
Chapter LIII., page 382. 

Experiments carefully made by the writer indicate 
that there is a constant relation between this expansion 
and the preceding shrinkage and forcibly demonstrate 
the necessity of “feeding” a casting to make its inte¬ 
rior solid. This is a matter with which all makers and 
users of castings have experienced difficulty. The 
founder being heretofore unable to define correctly the 
principles involving the urgent necessity of “feeding,” 
has failed to impress the moulder with its importance 
in making sound castings. Heavy-work founders and 
moulders know that hard grades of iron shrink much 
more than soft grades, a fact for which no satisfactory 
explanation has heretofore been given. 

By recent expansion experiments I have discovered 
that hard grades of iron expand more at the moment 
of solidification than soft ones. Fig. 74, page 389, is 
a diagram recording four such experiments. 

The manner in which the automatic records were 
obtained will be described further on. It is sufficient 
to say at present that the scale of inches in the dia¬ 
gram measures the length of travel of the pencils on 
the long recording-arms of the apparatus employed, 
not the actual length of expansion. The end of the 
short arm of each lever, following actual expansion, 
travels inch for 1 inch traveled by the pencil^ and 
the length of the test bars being 48 inches, 1 inch of 
the expansion or contraction record represents an 
actual expansion or contraction of 3 in 1536, or 0.195 


3 S8 


metallurgy of cast iron. 


per cent. For the purposes of these experiments, how¬ 
ever, the actual expansion or contraction was not re¬ 
quired. 

The significance of these diagrams is qualitative and 
comparative; and for this use of them the reading of 
the pencil-travel in inches is accurate, the apparatus 
and operation being the same in all the tests recorded. 
With this explanation I return to Fig. 74, In each of 
the four casts shown, two test bars, 1 x 1^ inches in 
section and 4 feet long, were cast “open-sand” side by 
side in the same mould. Tests Nos. 1, 3, 5 and 7 were 
poured from the respective ladles which brought about 
100 pounds of the iron direct from the cupola. These 
tests comprised the softest iron of each cast and had 
the least expansion and contraction, as is shown by the 
diagram. For tests Nos. 2, 4, 6 and 8, the grade of 
the iron was changed, by means of pouring about half 
of the hundred pounds contained in the ladle coming 
direct from the cupola into an empty ladle, the bottom 
of which was covered with about three-quarters of a 
pound of brimstone. The metal in the ladle having 
the sulphur was then agitated with a half-inch wrought 
iron rod until fuming ceased, after which all dross was 
skimmed from the surface, when each ladle was poured 
into its respective test-mould. The addition of sulphur 
hardened the iron in these tests, thereby causing the 
increased expansion and contraction shown in the 
diagram. 

In Fig. 75, page 390, tests Nos. 9 and 10 illustrate 
another discovery made by this method of compara¬ 
tive tests, namely, that where free expansion is pre¬ 
vented, a greater contraction is effected in that part. 

Test bar No. 9 was cast between iron ends, so ar- 


EFFECT OF EXPANSION ON SHRINKAGE, ETC. 389 


ranged that the power of expansion was not sufficient 
to extend the distance between them, whereas No. io 
had sand ends to compose the mould, which gave full 
freedom for expansion, the same as in all other tests 
displayed in Figs. 74 and 75. The fact that hard 



3 

4 

5 

6 

7 

8 


1 


Sulphur, 0.028 per cent. 


Sulphur, 0.275 per cent. 


Sulphur, 0.032 per cent. 


Sulphur, 0.268 per cent. 


Sulphur, 0.025 per cent. 


Sulphur, 0.368 per cent. 


5 

L 


' Inches. 


(.First 
| Cast 

Silicon 

1.17 

vSecond - 
| Cast 

1 Sillcor 

1 0.97 

(.Third . 
( Cast 

Silicon 

0.94 

(.Fourth j 
f Cast j 

Silicon 

1.68 

7 Inches. 

* 


FIG. 74. —DIAGRAM FROM AUTOMATIC RECORDS OF EXPANSION AND 
CONTRACTION, VARIED BY ADDITIONS OF SULPHUR. 


grades of iron expand more than soft ones, and the 
fact that retarding expansion gives rise to a greater 
contraction than where free expansion is permitted, are 
important as suggesting for works making such spe¬ 
cialties as chilled rolls, car-wheels, etc., in which heavy 




















METALLURGY OF CAST IRON. 


39° 

losses are often experienced through chill-checks and 
cracks, the advisability of adopting expanding and con¬ 
tracting “chills” wherever this may be practicable. 

Tests Nos. ii, 12, 13 and 14, in Fig. 75, illustrate 
the expansion and contraction of different sizes of bars 
poured in pairs from the same iron. T hese tests show 



13 

14 


CONTRACTION SIDE. 

3 4 5 6 

-1-1-1-h 


Size of Bar 1 x 1 % x 4 ’ 


Size of Bar l x \%"x i' 


Size of Bar 2 "x 2 \£x i' 


Size of Bar l"x 1 ^ x 4 / 


7 Inches. 


.Fifth 

Cast 


fe 


. 1.10 
0 . 05 ! 


11 

1 

Size of Bar 1 ^ x 2 x 4 

1 

\ 

1 



(.Sixth 

12 

1- 

Size of Bar 1 x "x 4 , 

-— 1 

(Cast j 


Si. 1.02 
S. 0.02! 


( Seventh 
Cast 


i Si. 1 . 
S. 0.1 


18 

01 


l 


2 

JL 


1 


12 3 

J_I_L 


4 5 6 

J_I_L 


7 Inches. 

j 


FIG. 75 . —DIAGRAM FROM AUTOMATIC RECORDS OF EXPANSION AND 
CONTRACTION, VARIED BY CONFINING EXPANSION AND 
BY USING BARS OF DIFFERENT SIZES. 


that large bars expand so as to increase their interior 
space more than small ones, thereby calling for the 
greater “feeding” in massive castings. These tests 
indicate also that light bars contract more than heavy 
ones, an element not to be overlooked in proportion¬ 
ing casting so as to avoid internal strains so far as 
practicable, a quality also seen on page 420. 

















EFFECT OF EXPANSION ON SHRINKAGE, ETC. 391 

The “ open=sand ” method of casting test bars affords 
the means of making comparative tests tinder varied 
conditions and gives an excellent opportunity to ob¬ 
serve characteristic phenomena at the moment of solid¬ 
ification, etc. In casting test bars of hard iron, a 
pronounced shrinkage along the upper surface is often 
noticed during the period of expansion; and often be¬ 
fore expansion is over there may be seen through 
shrink-holes at the hottest part of the bar (namely, at 
the point where it was poured,) that the interior is still 
liquid, showing that it is not necessary that the whole 
body of the casting shall solidify before expansion 
takes place. In this phenomenon, we perceive also 
the simultaneous action in the casting of two opposite 
tendencies, shrinkage going on in some parts, while 
expansion is occurring in others. 

It is the general impression among moulders and 
founders that the hotter the iron is poured, the more 
it will shrink, that is, the more the casting will require 
to be “fed.” This is an error into which the moulder 
has fallen by reason of the longer time occupied in the 
cooling or shrinkage of the “hot’’-poured metal, and 
consequently the longer period of “feeding.” The 
total addition of iron required in the “ feeding-heads ” . 
is no greater with “hot” than with “dull’’-poured iron, 
unless the “hot’’-poured metal has more largely pene¬ 
trated, fused or strained the walls of the mould. 

Numerous experiments have failed to show me any 
effect produced upon the total expansion by changes in 
the temperature of the metal when poured. Such an 
effect would not be naturally- expected, since the ex¬ 
pansion begins only with solidification, and the tem¬ 
perature of solidification, it is reasonable to say, is 


39 2 


METALLURGY OF CAST IRON. 


always the same for the same grade of iron, under the 
conditions of these tests; so that, however “hot” 
iron may have been poured, it will always have a cer¬ 
tain temperature when it begins to expand. But it is, 
of course, clear that expansion will take place sooner 
in a “ dull’’-poured bar than in a “hot” one; and 
again, a light body will expand more quickly than a 
heavy one, as I have proved by my tests. 

The length of the period of expansion varies with the 
size of the casting. The more massive the casting, 
the longer the period of expansion. In the bars 
shown in Figs. 74 and 75, the expansion lasted from 
one-half to one minute in the smallest bars, and, in 
the largest bars, from three to five minutes. The re¬ 
lation between the shrinkage and the expansion of 
solidification may now be indicated. The author’s 
view is that the apparent shrinkage of liquid metal 
so familiar to heavy founders is not due chiefly to a 
change in the specific gravity of the liquid metal as it 
passes to a solid state, but largely to the effect of the 
expansion of the solidifying parts of the casting. 
That is to say, an outer shell of the casting being first 
formed, its expansion at the moment of solidification 
necessarily enlarges the interior space to be occupied 
by liquid metal; and either additional liquid metal 
must be applied or else cavities and shrink-holes will 
be found in the interior of medium and heavy cast¬ 
ings, by reason of the progressive accretion of the 
solidifying metal upon the parts already solidified. Such 
cavities would, on this hypothesis, be likely to be most 
abundant in the portions which solidify last; and that 
this is in fact the case, is often proved by practice. 
Cavities are very liable to occur in the interior of 


EFFECT OF EXPANSION ON SHRINKAGE, ETC. 


massive castings, and even when castings are properly 
proportioned the portion a-round the “gates” which 
convey the metal to the mould is often very likely to 
be porous or to exhibit shrink-holes, due to the cir¬ 
cumstance that the metal solidifies last at these 
points, and to the attraction of solidifying particles to 
the already solid mass. This hypothesis explains also 
the fact that, in heavy castings, poured “ hot,” shrink¬ 
age is not often exhibited in the “ feeding-heads ” un¬ 
til long after the pouring, and that when it does com¬ 
mence (which is not before some expansion has taken 
place, due to parts solidifying,) it is often so rapid as 
to require, for a short period, constant additions of 
molten metal. 

Expansion at the moment of solidification being 
thus one cause of shrink-holes in castings, the practice 
(not uncommon among moulders) of placing “ risers,” 
not much larger than lead-pencils, so to speak, on 
massive castings, thinking thereby to make them solid, 
is to be discouraged as useless. It follows, moreover, 
that a casting should be “fed” until expansion is 
ended. It is not while a metal looks “ hot ” or fluid 
in a “ feeding-head ” that attention is specially neces¬ 
sary to secure a solid interior; it is when the metal is 
thickening or “freezing” in the “feeding-heads” 
that the greatest attention should be paid to the 
“ feeding.” It is a general practice among moulders, 
at present, to let their “ feeding-heads ” “ bung up ” 
at a time when the greatest effort should be made to 
keep them open, so as to insure a solid casting. It is 
at this time that expansion is taking place, to enlarge 
the surface area, and consequently the interior volume 
of a casting, thereby causing the hottest or most fluid 


394 


METALLURGY OF CAST IRON. 


portion of the casting to be robbed of metal, which 
must be supplied, in order to prevent shrink-holes at 
all such points. 

According to the view here presented, it will be also 
easy to understand that the resistance offered by the 
mould may often affect the expansion and shrinkage as 
well as the subsequent contraction. Whether the 
power of expansion is as great as that of water in be¬ 
coming frozen, is, as far as I know, undetermined. I 
do know that by casting between iron yokes or flask- 
ends, the longitudinal expansion of the bar may be 
prevented, as is seen in Test No. 9, Fig. 75, In such 
a case, of course, it is natural to suppose that the ex¬ 
pansion must be in some other direction, and it may 
increase to a smaller degree the interior space neces¬ 
sary to be supplied with molten metal by feeding. 
The heat-conducting capacity of the mould, as deter¬ 
mining the rate of solidification, may also affect the ap¬ 
parent result. Thus, a casting made in an “ iron 
chill ’ ’ mould may show less shrinkage than if the same 
iron had been poured into a sand mould, because, in 
the latter case, the solidifying iron could have time 
and opportunity, by reason of the nature of the mould, 
to expand it more outward, thus increasing the inte¬ 
rior space to be supplied with molten metal as already 
explained. 

To return to the fact discovered by the writer, 
that hard grades of iron expand in solidifying more 
than soft grades, it may be said that this is contrary, 
not only to the general impressions, but also to the 
current explanation of the fact of expansion, which 
would ascribe it to the creation of graphitic car¬ 
bon. If this were the controlling cause, we should ex- 


EFFECT OF EXPANSION ON SHRINKAGE, ETC. 395 

pect soft irons, which exhibit after solidification 
more graphite, to show the greater expansion. 

The formation of graphite is confessedly promoted 
by silicon, and hindered by the metalloids which 
“ harden ” the iron. When these metalloids are pres¬ 
ent in such proportions as to overpower the effect of 
the silicon, combined carbon, instead of graphite, is 
produced in the solidified metal, and the individual 
grains, crystals, or structural elements of the cast 
iron are consequently smaller and more densely 
packed in hard than in soft grades of such iron. Ex¬ 
pansion (and, perhaps, also contraction,) would be, 
therefore, exhibited by a larger number of such struct¬ 
ural elements in a given volume of metal, to be 
effected by changes in their form and size. This may 
explain the greater expansion shown by the hard 
grades in Tests Nos. 2, 4, 6, and 8 in Fig. 74, where 
the largest percentages of the antagonistic constitu¬ 
ents, silicon and sulphur, are presented. (See page 420.) 

But any theory on the subject may be premature. 
Far more important at this time is the fact itself, 
which affects so directly our foundry practice. I at¬ 
tribute the failure to detect it heretofore to the circum¬ 
stance that in the every-day work of the founder, the 
expansion of solidification does not force itself upon 
his attention. The shrinkage of the liquid mass, re¬ 
quiring “feeding,” is obvious enough; and so is the 
final contraction of the solid mass, for which allow¬ 
ance has to be made in the pattern. But the interven¬ 
ing expansion, not being marked b} 7 the final contrac¬ 
tion, has been overlooked. * 

I may here observe that the tests illustrated in Fig. 
74 refute the opinion heretofore advanced, that the 

* The subject of shrinkage is continued at the close of this 
chapter on pages 404 to 414. 



39 6 


METALLURGY OF CAST IRON. 


silicon contents of an iron can be defined from the 
final contraction of a casting or test bar. In all the 
bars of each cast in Fig 74 the silicon percentage 
was nearly constant. The variation in contraction, 
therefore, certainly justifies the assertion that the 
amount of silicon cannot be thus determined. In fact, 
the contraction will simply indicate the ‘ ‘ grade ’ ’ of 
an iron, and no more. The metalloids producing this 
“ grade ” can only be determined by analysis. 

The “ grade ” of a cast iron, as I use the term, is a 
practical name, familiar to heavy founders, though 
perhaps not capable of precise scientific definition. It 
is characterized by the degree of hardness, and inci¬ 
dentally by accompanying properties of contraction 
and of strength. This question of “ grade ” is further 
discussed in Chapter XX. 

It has been maintained that it is difficult to make 
cast iron absorb sulphur and that the founder has no 
need to fear sulphur in general founding.* In the tests 
shown in Fig. 74, the amount of sulphur in the iron 
was easily increased by the method described, as 
is proved by the subsequent analysis. At all events, 

I am sure that up to 0.3 per cent, sulphur can be 
easily present in cast iron containing about 2.00 per 
cent, of silicon, which is a percentage of silicon often 
permissible and practicable as a maximum in light 
castings, where the sulphur can be kept below 0.06 
in the castings produced. As o. 2 per cent, of sulphur 
is sufficient to injure or ruin almost any casting made 
for other purposes than sash-weights, the ability of 
cast iron to absorb as high as o. 3 per cent, of sulphur 
forcibly illustrates the great reason why the founder 
has to fear sulphur in fuel, high-sulphur iron, and to 

* This was advanced by reason of results derived from ^-inch 
test bars, in a lengthy paper seen in Volume XXIII. of the 
Transactions of the American Institute of Mining Engineers. 



EFFECT OF EXPANSION ON SHRINKAGE, ETC. 


397 


avoid any method in melting-, favorable to the absorp¬ 
tion of sulphur by iron in cupola or “air furnace ” 
practice. These considerations are applicable also to 
the making of iron in the blast furnace. 

The apparatus used for obtaining the expansion 
and contraction records, shown in Figs. 74 and 75, 
is shown in Figs. 76, 77, 78, and 79. It was designed 
by the author after much study of the conditions 
necessary for automatic record of the expansion and 
contraction of test bars, and also for the highly im¬ 
portant purpose of simultaneous comparative tests. 

The figures illustrating this apparatus (which is 
freely offered for use to all who may be interested in 
the matter) will be readily understood, with the aid 
of the following explanation: 

In Figs. 76 and 77 the same letters indicate the 
same parts, namely:— 

A, stationary or sliding recording face-plate board; 
B, float; D, float-receptacle; E, regulator, giving 
constant head of water; F, supporting arm for the 
water-supply vessel; H, over-flow pipe; K, L and M, 
recording arm levers; N, lead-pencil recorder; O, rub¬ 
ber-band lever-supporter; R, curve-recording face¬ 
plate board; S, slide-guides for recording curves; T, 
revolving sheave-wheel guide and support; U, fulcrum 
cross-bar; Y, supporter of fulcrum cross-bar. 

In Fig. 78 the parts are indicated by letters, as fol¬ 
lows : 

A, counterbalance clock-weight; B, bed-plate, se¬ 
curing the base board; I, one-day “ Pirate ’’ alarm- 
clock; R, curve-recording face-plate board; S, remova¬ 
ble casting-pin; U, fulcrum cross-bar; V, clock and 
recording face-board connecting-shaft. 



FIG. 76. —AUTOMATIC RECORDING APPARATUS FOR EXPANSION 

AND CONTRACTION. 













EFFECT OF EXPANSION ON SHRINKAGE, ETC. 399 

In Fig. 79 the parts are indicated by letters as fol¬ 
lows: 

A, expansion and contraction-end equalizer; B, 
spring-clasp; D, flow-off recess; E, spring-clasp iron; 
F, lever-fulcrum bearing; H, casting-pin clasp-open¬ 
ing; K, removable casting-pin. 

The levers of this apparatus are so delicately 
mounted as to be moved by a breath. As already 
stated, for every inch travel of the long arm, the 
short arm, moved by the actual expansion or contrac¬ 
tion, travels three thirty-seconds of an inch in the 
straight line. The diagrams, Figs. 74 and 75, pages 
589 and 390, were constructed by platting the sum of the 
readings given by the pencils at the two ends of the ap¬ 
paratus in straight lines, and consequently give only the 
total longitudinal expansion and contraction, without 
indicating rate or alternations. But the apparatus can 
be employed, with the aid of the float or clock, etc., 
shown in the figures, to record curves. For a straight 
line record, the face-plate, A, Figs. 76 and 77, is held 
stationary. To obtain curves, it is gradually lowered 
at any desired rate by means of the float B, in the 
receptacle, D, Fig. 77, a constant head of water being 
maintained in the reservoir, E, by a supply from a 
suspended vessel at F, and an overflow-pipe, H. A 
specially arranged strong spring clock might be used 
instead of the float B, to lower this face-board uni¬ 
formly, so as to effect the same end, and with either 
plan introduce into the results the element of time. 
Incidentally, such experiments ought to settle the 
question whether there are, as has been declared, two 
periods of expansion in cast iron when it is cooling, 
after the liquid metal has “ frozen,” or solidified. 



FIG. 


77.—AUTOMATIC RECORDING APPARATUS 
OF FIG. 76), WITH ARRANGEMENT FOR 


(SEEN FROM OPPOSITE 
RECORD IN CURVES. 


SIDE 







EFFECT OF EXPANSION ON SHRINKAGE, ETC. 


40 1 


The lever-arms, K, L and M, Figs. 76 and 77, are 
held gently against the face-plate by light rubber bands, 
secured midway in their lengths at O, so that the very 
soft pencils at N may record all movements of these 
arms. The pencil-record may be made on paper, cov¬ 
ering the face-plate, as indicated in the figures, or on 
the bare face of the recording-board. 



It will be evident that the records of the 
independent levers at each end of the bar 
must be added together, in order to deter¬ 
mine the total expansion or contraction. 
Thus, in the case of test No. 1, Fig. 7 4, the 



FIG. 78. —INDEPENDENT DIAL FOR RECORDING EXPANSION 
AND CONTRACTION IN CURVES. 


automatic record of the apparatas would show a 
travel in expansion of one-half an inch at each end, 
or one inch in all, followed by a contraction of two 
and one-half inches at each end, or five inches in all, 
not including the retracement of the previous expan¬ 
sion. In other words, after expansion was ended, the 
bar contracted longitudinally eighteen thirty-seconds 
of an inch (each inch of the pencil-line representing 














I IG. 79.—TEST BAR PATTERN AND LEVERS FOR RECORDING APPARATUS 





















EFFECT OF EXPANSION ON SHRINKAGE, ETC. 403 

three thirty-seconds of an inch of the short-arm lever- 
movement, i. e., of actual extension of the bar); and 
consequently, the test bar, 48 inches long as poured, 
was elongated in solidification to 48-3 3 2 inches, and then 
contracted in cooling to 47IJ inches, its final length 
at atmospheric temperature. 

The clock shown at I, Fig. 78, with its face-plate, 
R, can be set independently, with a single recording- 
lever, to receive on the revolving face expansion and 
contraction curves from one end of the bar only, or it 
can be supported, as shown in Figs. 76 and 77, so as to 
record curves in connection with the records made 
on the stationary or sliding face-board, A. 

The whole apparatus is of wood, except the fulcrum 

bars, U, Figs. 76, 77, and 78, the casting-pin, S, Fig. 

75, and the pin-holding plates, E, Fig. 76. By a 

study of these levers in Fig. 79 it will be seen that a 

little pressure on the spring side at B will instantly 

release the casting-pin seen at K. The yh" casting- 

• _ 

pins seen at S, Fig. 78, and in position at K, Fig. 79, are 

made tapering, so that they can be readily moved 
from a test-bar and used again. They cause the levers 
to record sensitively any movements due to expansion 
or contraction after the bars are poured. At the left 
of Fig. 79 is seen the form of pattern used for mould¬ 
ing the test bars. The projection at A is cast on, as 
shown, so as to insure equal action in recording the ex¬ 
pansion and contraction at each end of the bar. At D 
is a recess, which gives guide to make the same in 
the mould, so that in pouring the bars “ open-sand,” 
the metal will “ flow off ” at this point when it comes 
to that level, and thereby insure all bars being cast 
closely to the same thickness. 


APPENDIX TO CHAPTER LIV. 


A few illustrations of shrinkage and blow holes 

which the author gave, with other subjects, in a 
lecture before the students of Cornell University, 
December 14, 1900, and published in the Sibley Jcnir- 
nal of Mechanical Engineering, January and February, 
1901, are presented here, as they contain illustrations 
that are important to be treated in connection with 
the subject of expansion, shrinkage, etc. 

When a shrink hole or holes occur in a casting they 
will always be found in the part or parts which solidify 
last. To prevent such holes in castings, we must pro¬ 
vide means to fill the void space with metal. It is 
often difficult and again it is impractical to do so. The 
chances for such holes occurring are often due to the 
design. There are times when, if the constructing 
engineer or designer thoroughly understood the cause 
of shrink holes and their remedy, he could design or 
proportion his castings to avoid such evils. The ques¬ 
tion might be asked, how is a person to know which 
will be the last part or parts of a casting to solidify, or 
where we may expect the shrink holes? Such holes 
will always be found in the upper cast part of uniform 
solid castings, as seen at E in sample No. 18, Fig. 80, 
and in the body of heavy sections having light ones 
joining them, as at F, sample No. 19; that is, if in both 
cases such bodies are not fed with additional metal to 
feed the shrinkage. Where light parts join heavy ones 


APPENDIX TO CHAPTER LIV.-TREATS SHRINKAGE. 405 

the light parts, solidifying first, will naturally obtain 
all the metal required to feed their shrinkage from the 
heavy part. For this reason if we do not, in turn, 
supply the heavier part with additional metal we may 
expect some excessive cavities or shrink holes in them, 
unless we have reason to suspect that the creation of 



FIG. 80 .— CASTINGS SHOWING TYPICAL POSITIONS OF SHRINK HOLES. 


graphite to enlarge the grains of iron is such as to 
compress the metal in such a manner as to prevent the 
existence of shrink holes. Then again, there are cases 
where the expansion of cores on the interior of cast¬ 
ings, while the metal is in a molten state, will compress 
the metal so as to fill up any cavities that might be 
caused in a natural way. 

A good illustration which shows how light parts will 
often draw metal from heavy ones and leave cavities 





406 


METALLURGY OF CAST IRON. 


in the latter, is a section of a locomotive pump casting 
made some years ago in Cleveland, Ohio, and causing 
such trouble that it went the rounds of several foundries 
before good castings were obtained. A section of this 
casting is seen in Fig. 81. It will seem strange to many 
unfamiliar with founding that moulders did not under- 



SIBLEV JOURNAL. 

FIG. 8l.— LOCOMOTIVE PUMP CYLINDER SHOWING POSITION OF SHRINK 

HOLES. 

stand how to make such castings sound, but if any 
such ever come to have experience with foundries and 
moulders, they will find that too many of them are 
ignorant of the principles underlying the art of found¬ 
ing. The difficulty with the pump casting lay in there 
being cavities found at about G, as marked in Fig. 81, 
when the section was bored out to form a valve seat. 
These pumps were cast on end and at all angles; many 
were made with good large skimming gates to 
hold back the dirt, thinking such to be the cause of the 
imperfection found. Besides this, they went so far as 
to make them in dry sand, but all of no avail. Finally 













APPENDIX TO CHAPTER LIV.-TREATS SHRINKAGE. 407 


the castings came to the hands of a moulder who 
understood the cause of shrink holes and could tell such 
cavities from blow or dirt holes. After this moulder 
had made one mould and observed the proportion of 
thicknesses in the casting, there was no more trouble. 
The difficulty had lain in not providing means to con¬ 
vey hot metal to supply the shrinkage of the heavy 
part. This was done by attaching a feeder, as at H, 
having a connection with the casting, as at J, both 
bodies of which were so much larger in area than the 
section of the casting at G that assurance was afforded 
that the metal would solidify in the heaviest section of 
the casting at G before it would do so in the feeders H 
and J, thus giving a head of molten metal which could 
settle down from the feeder to make a solid casting. 
Pouring these castings on end, instead of on their flat, 
could do no good, as the metal would solidify first in 
the thin part of L long before it would do so in the 
heavy section of G. If a heavy feeder as at the dotted 
line M, made of the same 
proportions as J and H, had 
been carried down from the 
top of the up-ended mould 
to the heavy section, sound 
castings would have been 
produced, but otherwise 
they were as well made 
on their flat as on their 
end. 

Another illustration of 

this principle of feeding is 
found in not obtaining 


SISLEY JOURNAL.^ 

FIG. 82. — CYLINDER SHOWING POSI- 

sound flanges, as at N, Fig. tion of shrink holes. 















408 


METALLURGY OF CAST IRON. 


82, with cylinders cast on end. The feeding head O, 
which is intended to supply the shrinkage of all below 
it, is often made so small that it solidifies before the 
heavy portion at P, and then what metal settles to 
supply the shrinkage of the lower body of the casting 
P comes from the thicker or more fluid section at N, 
and leaves shrink holes at that point. This whole 
difficulty could be stopped by making the feeding head 
O larger, as per dotted line R, as then this would be 
the last to solidify, and when the feeding head O was 
cut off to give a finished flange a solid body of metal 
would be found under it, providing the feeding head 
O had been fed with hot iron by means of a feeder or 
heavy riser head (not shown) placed on top of the 
feeding head O as is the common practice. 

Blow holes. Having treated the subject of shrink 
holes, we will say a few words on what are called blow 
holes. Such holes may often appear to some as shrink 

holes, but they gen¬ 
erally differ in be¬ 
ing found in lighter 
parts of castings, 
than where shrink 
holes are liable to 
be found, and are 
generally of a 
smoother charac¬ 
ter. Not only are 
blow holes found 
on the interior but 
the exterior as well; 
in either place, they 
fig. 83. —castings showjng blow holes, are caused by gases 






APPENDIX TO CHAPTER LIV. 


TREATS SHRINKAGE. 409 



that were not carried off from the mould through 
proper channels of venting the sand, or oxides and 
slag in the metal giving off gases that, in an effort 
to escape from the metal, become imprisoned in 
a casting, as seen at S, sample No. 22, Fig. 83. 
This is caused by reason of the metal solidifying 
before the gases could rise upward to find relief 
through the cope or top part of the mould, and which, 
if not well vented, or of a porous and fairly dry char¬ 
acter, will then often hold the gases from going further 
and form cavities in the cope side of castings, such as 
seen at T in sample No. 23 of the same figure. 

A description of 


some special tests on 

shrinkage, contrac¬ 
tion, specific gravity, 
and fusion that the 
author made and pre¬ 
sented in a paper to 
the Western Found- 
rymen’s Association 
at Cincinnati, 1897, 
are given in the fol¬ 
lowing. Prior to 
these tests we did not 
possess any informa¬ 
tion as to what per¬ 
centage of shrinkage 
there existed in iron when cooling from a fluid to a 
solid state. Realizing the advisability of obtaining such 
information, the author devised the following method 
of testing the shrinkage of the different metals shown 
in Table 86, page 411, and illustrated by Figs. 84 and 85. 


FIG. 84. —SHRINKAGE PATTERN AND TEST 
' CASTING. 







4 io 


METALLURGY OF CAST IRON. 


At M, Fig. 84, is seen an iron pattern from which 
sand or chill moulds may be made. At A, Fig. 85, is an 
iron box three inches square by eleven inches long, in 



FIG. 85. 

which the pattern M has been moulded to make a dry 
sand mould and is filled with molten metal. The cut 
shows a moulder in the act of pouring the contents 





APPENDIX TO CHAPTER LIV.-SHRINKAGE, ETC. 411 

of the mold into a chill or all-iron mould. This is split 
in halves, as will be noticed, and a ring clamp, as at 
B, is used to hold it firmly together, E being a bottom 
block for the chill proper to rest on, and D a funnel 
cap placed loosely on the top of a chill to insure the 
stream of metal being guided directly into the chill 
mould without any being spilled. Before pouring these 
moulds they are tested to learn if their cubic contents 
for holding metal are exactly alike, by means of filling 
one with fine hour-glass sand, and then pouring the 
same into the other. This is done only as a precau¬ 
tion to make sure that no extra thickness of blacking 
or distortion of the dry sand mold has occurred in any 

manner while making it. There are three of these 
• 

dry sand moulds made for each cast or test of any one 
grade of metal, two being called portable and one 
stationary. The plan of using these moulds is as fol¬ 
lows: A portable mould is secured in the ladle shank 
and the small cupola (page 241) tapped to fill it direct, 
and it is then quickly poured into the chill mould as 

TABLE 86.—SHRINKAGE AND CONTRACTION OF GRAY AND 

CHILLED IRONS. 


Heat Nos. 

1 

2 

3 

4 

5 

6 

Character of metal 
tested. 

Ferro- 

silicon. 

Foundry 

iron. 

Bessemer 

iron. 

i5t steel 
with 

gray iron 

Charcoal 

iron. 

Charcoal 

iron. 

Silicon. . 

12.25 

i -75 

1.72 

1.61 

•75 

.70 

Sulphur... 

.021 

.04 

•054 

•055 

•03 

•035 

Shrinkage of 

chilled iron 

3 oz. 
240 gr. 

2 oz. 
240 gr. 

2 oz. 
180 gr. 

2 oz. 
290 gr. 

6 oz. 

6 oz. 
280 gr. 

Shrinkage of 

gray iron .... 

3 oz. 

1 oz. 
210 gr. 

1 oz. 

140 gr. 


1 oz. 
460 gr. 

2 oz. 

120 gr. 

Contraction of 

chilled iron... 

. 270 " 

.262" 

.271" 

.322" 

.446" 

.460" 

Contraction of 

gray iron .. 

.24 " 

.205" 

.211" 

.227" 

.229" 

• 235" 
































































412 


METALLURGY OF CAST IRON. 


above described and seen in Fig. 85. This done, the 
first sand mould is removed from its ladle shank and 
another set in to replace it. This in turn is also filled 
with metal, and instead of pouring this into a chill it 
is poured into the stationary sand mould, after which 
it is then removed and placed with its mate. We 
now have two moulds, one a chill and the other a 
sand mould, that will have a sunken space at the neck 
K, Fig. 84. To learn the amount of shrinkage that 
has taken place, the shrunken and unfilled spaces at the 
necks of the chill and the dry sand castings are now 
filled with molten metal and separated from the main 
casting, views of which pieces are seen at E and H, 
Fig. 84. The straight portion at H is that created by 
the shrinkage, which takes place as the metal is being 
poured, and the portion at E, which is irregular in out¬ 
line, is that created by the shrinkage of the molten 
metal in cooling to a solid, to leave a cavity in the 
main body of the roll as seen at the right of Fig. 63, 
page 338, after the moulds have been poured and are 
released by splitting the end of the roll at K. The 
piece at E is the other end up from that shown before 
being removed from the roll K. A little study of the 
sections E and H will show that their total weight (by 
fine apothecary scales), minus any thin wafer sheets of 
iron that might be found sticking to the walls of the 
dry sand mould, that had not run out as metal to test 
the shrinkage, would be the shrinkage of that iron 
under the conditions in which it had been poured. 

By referring to Table 86, page 411, it will be seen 
that we have, in castings measuring about two and a 
quarter inches diameter by seven inches long (the 
actual form and size being seen at M, Fig. 84), weigh- 


APPENDIX TO CHAPTER LIV.—SHRINKAGE, ETC. 413 

ing nearly eight pounds, a shrinkage in the chilled 
iron of about six ounces, and in the gray about two 
ounces. This means a shrinkage of about four and a 
half pounds per hundred for all chilled iron, and nearly 
two pounds per hundred for all gray iron. In larger 



FIG. 86.—CONTRACTION TEST WITH CHILL AND SAND MOLDS, AND 

PATTERNS. 


figures, for example, with a twenty-ton casting, Table 
86, would imply a shrinkage of about 1,800 pounds for 
all chilled iron were it possible for all of its body to be 
as thoroughly chilled as is the section of rolls seen in 
Fig. 62, page 337, and 800 pounds for the gray iron if 
the total body of the casting does not get up in 
graphite any higher than the rolls hold it, as seen in 
Fig. 61, page 333. 








414 


METALLURGY OF CAST IRON. 


It is to be remembered that the tests of iron shown 
in Table 86 do not include an iron as soft as is neces¬ 
sary for stove plate or very light castings, and because 
such grades of iron are softer than any shown in Table 
86 they would possess less shrinkage. The tests exhib¬ 
ited by Table 86 demonstrate positively that metal will 
shrink and cause trouble by leaving holes in the in¬ 
terior of castings, and also that the greatest shrinkage 
exists in the harder grades of iron. 

The relation that contraction maintains to shrink- 
age, with the same metals .(see page 386), was another 
point which the author thought well to obtain knowl¬ 
edge of while conducting the experiments on shrinkage. 
In order to test this factor the author devised the appli¬ 
ance seen in Fig. 86, and which permitted casting bars 
seen at the left of this figure in a sand and chill 
mould, to test, together with other qualities, the differ¬ 
ence in contracting that would be caused by rapid and 
slow cooling of the same metal. By Table 86 we 
find that tests Nos. 1 and 6 give us the mean of .127 
greater contraction for the fast cooled bars than for 
the slow cooled ones, each of the same cross section 
and length, patterns for which are seen at the left of 
Fig. 86. The greatest difference in Table 86 is . 225 and 
the smallest .030. It is to be remembered that the 
respective tests seen in Table 86 were cast in their 
order with the same gate and hand ladle of iron. The 
cause of such a difference in the contraction of two 
bars is, as will be seen by Fig. 86 at N, that one is 
cast in a chill mold and the other in sand, P being the 
space for molding the sand bar. A study of the differ¬ 
ence in contraction which the rate of cooling can cause 
by the device seen at Fig. 86 is instructive in more 


APPENDIX TO CHAPTER LIV.-CONTRACTION, ETC. 415 

ways than one. Take the case of the charcoal iron 
heats Nos. 5 and 6, which will illustrate the great diffi¬ 
culties the makers of chill rolls, etc., are confronted with. 
Here we find that the chilled part of the casting will have 
as much again contraction as the body of the casting 
that is not chilled. It is no wonder that chill roll 
makers experience much trouble with the checking 
and cracking of the surfaces of chill rolls due to the 
excessive contraction of the chilled parts, which must 
leaye or pull away from the chill mold supposed to 
support its enclosed body of liquid metal long before 
it has solidified, and, which by reason of its head pres¬ 
sure incased within the body of the shell, that has 
contracted from its chill or outer support, must be 
heavily strained to retain its enclosed body of still 
fluid metal. We can see by the chill and sand contrac¬ 
tion tests, herein recorded, how a very slight difference 
in the dampness of sands or nature of a mould can 
affect the contraction of castings or test bars, and 
shows us the necessity of having uniform conditions 
in moulds and temper of sands in order to obtain a 
true comparative record of contraction tests. More 
on this subject is found on pages 454, 467 and 511. 

Comparative fusion tests by immersion were con¬ 
ducted at the same time that the shrinkage and con¬ 
traction tests were made. This was done chiefly to 
test which of the chilled or sand cast ends of one bar 
would melt first of the various metals used. The device 
the author designed for these tests is shown in Figs. 
87 and 88, the former figure shows a three-quarter- 
inch rod in the hands of a moulder being held over a 
ladle that holds in its end a casting made in the mould 
seen at Fig. 88. The upper half S was all green sand 


416 


METALLURGY OF CAST IRON. 



FIG. 87. —LIQUID BATH COMPARATIVE FUSION TEST. 

a softer or more complete gray mixture, which if held 
in a bath of molten iron or steel would be a very pro¬ 
nounced test to assist in showing whether hard or soft 
grades etc., of iron, when charged into a cupola or air 


held in a wooden box, and the lower a chill or iron 
mould made in halves and held together by a ring T, 
the whole resting on a bottom block U and the metal 
being poured in at Q. Now it will readily be seen 
that a casting made in such a mould would have one- 
half wholly chilled or body hardened, and the other of 








APPENDIX TO CHAPTER LIV.-TESTING FUSION. 417 

furnace, etc., as such, would melt the faster. The cut 
at Fig. 87 shows the exact appearance of the specimen 
as it was taken out of a crane ladle bath of molten 
metal, just as the chill end V was about to disappear 
entirely, and which we have found in all cases to melt 
away five to ten minutes faster than the gray end X. As 
the question of encouraging the manufacture of chilled 
or sandless pig by the blast furnaceman, which this 

work advocates, is an important one, 
the author would advise all to try this 
experiment, and in doing so many will 
find themselves surprised at the rapid¬ 
ity with which the chill or body hard¬ 
ened end melts, compared to the gray 
or soft end of the test specimen. In 
using this device, some judgment will 
have to be used as to the size of the 
test roll and of the ladle for its 
immersion. For a roll of two to three 
inches diameter a one thousand pound 
ladle or larger will be necessary, but 

FIG. 88. — COMPARA- 0 . . 

tive fusion test rolls about one inch in diameter can 
mold. often be melted down in a bull ladle 

holding two to three hundred pounds of iron, before 
the metal would get too dull. These rolls are well 
made, about twelve inches long, and are secured by 
the end of the rod seen curved around it tightly in 
the center. All sand and scale should be well filed 
or ground off from the sand end of the roll so as to 
have it free from foreign matter, similar as in the 
chilled or hardened end, to make conditions alike in 
each end as far as possible. Another plan for testing 
fusion is given on pages 231 and 314. 





CHAPTER LV. 


STRETCHING CAST IRON AND ELEMENTS 
INVOLVED IN ITS CONTRACTION.* 

What shall I allow for contraction ? is a question 
which the experienced pattern-maker will generally 
ask the moulder or founder before any patterns of im¬ 
portance are begun. It is true, we have the stereo¬ 
typed rule of allowing one-eighth of an inch per foot 
for contraction, and many pattern-makers and found¬ 
ers are so inexperienced as to accept such a rule for 
the contraction of every form and thickness of a pat¬ 
tern which their plant may be called on to make. It 
is possible with the class of work which they make 
that such a practice may never have led them into 
difficulties, and hence they obtain an experience which 
would lead them to believe that there are no conditions 
calling for anything else than the making of all pat¬ 
terns one-eighth of an inch per foot larger in every di¬ 
rection than the castings desired. 

Moulders and founders of broad experience in gen¬ 
eral machinery work know that there will generally 
be a difference in the contraction in any two forms 
that differ in their proportions, even when poured 
with the same iron. Also the form of a mould and 

* Read by the author at the meeting of the Western Foundry- 
men’s Association, at Chicago, Nov. 20, 1895. 



STRETCHING CAST IRON, ETC. 


419 


the manner in which it is made and the casting is 
cooled, have much to do with the size of the casting, 
as compared with the pattern from which it was made. 
It is not the intention of the author to attempt to set 
forth fixed rules for the contraction of castings by 
the classification of the different kinds of work, as 
some have done, for this is not practical, but more to 
call attention to the principles involved and assist the 
engineer, founder, moulder and pattern-maker to best 
judge what contraction, if any, should be allowed for 
constructing patterns, to meet the various conditions 
in moulding, mixing of metals and cooling of castings. 
Not only has the experienced heavy-work founder 
found a great difference to exist in the contraction of 
the same kind of iron in different castings, but some 
will agree with the author in affirming that instead of 
allowing for contraction, the reverse conditions occa¬ 
sionally prevail and are elements frequently necessary 
to be considered in making patterns. It is nothing 
unusual for moulders and founders engaged in heavy 
or jobbing machinery to find their castings much 
larger than the patterns from which they were made, 
thus disclosing a condition in founding of which the 
light-work founder and ‘ ‘ stove plater ’ ’ would have no 
opportunity of obtaining any knowledge. Before the 
author discusses the qualities involved in stretching 
cast iron, which is an important part of this paper, he 
will consider those effecting a difference in thick and 
thin bodies cast under the same conditions or in the 
same flask with the same iron or ‘ ‘ gates ’ ’ and from 
which observing founders have learned that a heavy 
casting or parts will contract much less than a light 
one, where conditions permit of free contraction. 


420 Metallurgy of cast Iron. 

An experiment which the author conducted to dem¬ 
onstrate the fact just cited was to take a pattern 14 
feet long by four inches by nine inches, and another 
exactly the same length but only one-half inch by two 
inches, and cast both together with the same gates. 
Although the bars were of the same iron, a difference 
of seven-eighths of an inch existed in their contrac¬ 
tion. The thin casting contracted one and three-quar¬ 
ters of an inch, whereas the thick contracted seven- 
eighths of an inch. Why is this? is a natural question, 
and in answer the author would offer the following 
hypothesis: 

The carbon held in fluid iron, authorities claim exists 
in a combined form. How much of this will change to 
graphite when the castings or iron has solidified and 
become cold enough to handle, depends first upon the 
time of cooling, and second, the percentage of sulphur, 
silicon, manganese, and phosphorus, which exists in 
the iron.* The greater the silicon up to nearly four 
per cent., also the phosphorus up to one per cent., and 
the lower the sulphur and manganese, taking account 
also of the time consumed in cooling, the higher we 
will find the graphitic carbon. The greater the for¬ 
mation of graphite, the more open, or larger the 
grain of the iron ; and this is one secret of thin 
castings and hard iron contracting more than thick 
castings and soft iron, in cases where all conditions in 
moulding, cooling and freedom for contraction are sub¬ 
stantially alike. For other qualities effecting this, 
see pages 394 to 396. 

Two castings from one pattern, of the same iron, can. 
by cooling one more quickly than the other, be made to 
show considerable difference in their contraction, ow- 


* i he total carbon 3s also to be included when thought to vary 
from any given standard. 3 



STRETCHING CAST IRON, ETC. 


421 


ing to one having a greater time for large permanent 
flakes of graphite to form, a quality the author noted 
in a paper before the Foundrymen’s Association at 
Philadelphia. See Chapter LIX, page 454. This 
chapter also presents analyses of one-half and one inch 
square as well as one and one-eighth inch round test 
bars poured from the same ladle at the same time, 
showing that the graphite was much less in the one- 
half inch than in the one and one-eighth inch test bars, 
and on this account contraction was much less in the 
larger than the smaller bars. 

The formation of graphite may be compared to the 
cooling down or evaporation of a saturated salt solution. 
If slow, we get big salt crystals; if rapid, we get smaller 
ones. This is similar to the cooling of liquid iron to a 
solidified cold state. The longer the period for cooling, 
the greater the expansion of the molecules and grain of 
the iron, which is defined chemically by our having 
higher graphite in slow than in fast cooling ; this 
is also assisted by the heaviest parts of a casting or 
that last to solidify often containing silicon to have its 
percentage higher than will be found in the lightest 
portion or those first to solidify. (Expansion is also 
a quality affecting contraction which should be con¬ 
sidered in connection with graphite. For effects of 
expansion, see Chapter LIV.) 

We can take the worst kinds of scrap iron, and by 
pouring them into such heavy bodies, as anvil 
blocks, for example, obtain iron that presents a large, 
open-grained fracture, often of excellent texture, 
proper for being readily machined; whereas, were 
the same iron poured into a casting undei three inches 


422 


METALLURGY OF CAST IRON. 


in thickness, it would be “ white ” and hard as flint. 
In the former case, also, it would show much less 
contraction than in the latter. The facts go to 
show that the length of time occupied in cooling a cast¬ 
ing, or that molten metal has solidified, may often 
be more effective in causing different degrees of con¬ 
traction and hardness of iron in a casting from ordi¬ 
nary used foundry iron, than any varying percentages 
of sulphur, silicon, etc., which exist in ordinary found¬ 
ry iron. Any one giving due consideration to the 
points here raised will be led to concede the im¬ 
practicability of formulating set rules for the contrac¬ 
tion of castings, to be published as a universal guide 
to desired results in the dimensions of castings; but 
by a study of the phenomena here referred to, we will 
be in a fair position to determine what allowance 
should be made for contraction, etc., when we are on 
the ground of action. It is to be understood that ref¬ 
erence is not made to the difference which may exist 
in the size of like castings from soft and hard iron, or 
variations due to the hardness of ramming and head 
pressure of molten metal on moulds, etc. We are main¬ 
ly dealing with the elements involved in the question 
of contraction, as affected by rapidity of cooling, 
stretching of iron, and variations in the thickness of 
metal, etc., in castings. 

Stretching is possible and due to influences exerted 
by conditions in casting, cooling, and forms of patterns, 
which overcome or retard free contraction. It can make 
castings larger than the patterns from which they were 
made, and it also makes it possible to obtain acceptable 
castings which could not be secured were it not for the 
fact that iron can be stretched. 


STRETCHING CAST IRON, ETC. 


423 


The author will now describe a device which he has 
designed with the object of testing and proving that 
cast iron stretches as well as expands. While the cuts 
89 and 90, pages 424 and 425, will explain clearly to 
some the exact working of the device, I will describe 
it in detail in order that all interested can criticise and 
fully understand its construction and working. 

A, Fig. 90, is the pattern used. The shoulders at 
B and C are for the purpose of providing means to 
stretch the bar by clamping or holding one end to a 
support at D, Fig. 89, which has a recess forming a 
part of the iron frame at the end D into which the 
projection X of the test bar pattern A is inserted when 
moulding the bar, and which, when cast rigidly, pre¬ 
vents the test bar from contracting or pulling away 
from this end, the other end being pulled by weights as 
seen at E where one, two or more 50-pound standard 
weights are suspended over the roller H. There are 
two moulds cast side by side, “ open sand ” with inde¬ 
pendent runners R and T from the same ladle of iron 
as quickly as they can be poured. The only differ¬ 
ence existing in these two moulds, lies in one being 
strained by the weights, while the other is free from 
any weight or restraint to prevent contraction, other 
than the restraint of the mould’s sides, and this affords 
the most favorable arrangement to observe and record 
any difference which may exist in the contraction, 
etc., of free and restrained bars. Independent point¬ 
ers are attached to these bars by means of levers and 
show their readings on scales behind them. 

The first movement of the pointer to be noticed is 
its passing to the right of zero. This action com¬ 
mences about 30 seconds after the bars are cast and 


424 


METALLURGY OF CAST 


IRON 



FIG. 89.— WEST’S STRETCHING RECORDER 



















STRETCHING CAST IRON, ETC. 


425 


continues for about 90 seconds for a total travel of the 
pointer of about one and one-half degrees on the arc 
shown over the top of the pointer P. This is caused by 
the expansion of the metal at the moment of solidifi¬ 
cation, a quality, by the way, which some have disputed. 
After the expansion has fully recorded its influence, 
in lengthening the bar, the pointer P stands still for 
about two minutes, after which time contraction be¬ 
gins and the pointer P starts to move back to the left. 
The weights at E are now suspended, and it will be 
well to emphasize the fact that they exert no influence 



FIG. 90. —STRETCH PATTERN. 


X 


to suddenly move the pointer P backward to zero. 
Five minutes after the contraction commenced, the 
restrained bar’s pointer will have moved about one 
degree and the pointer on the free bar two and one- 
half degrees to the left of their starting points. About 
fifteen minutes after the bars are poured the restrained 
bar will have moved the pointer one and one-half de¬ 
grees and the free bar three and one-half degrees. At 
30 minutes after the pouring, the restrained bar will 
have moved the pointer three degrees, and the free 
bar about five degrees, showing in the time be- 





















426 


METALLURGY OF CAST IRON. 


tween 15 and 30 minutes after the pouring that the 
restrained bar held about even pace with the free bar. 

From this point on, the restrained bar keeps gaining 
on the free bar, until the end, when the free bar 
stands about one and one-half degrees ahead of the 
restrained or weighted bar’s pointer, thus showing we 
can restrict contraction by power and that the period 
of the greatest stretching of cast iron, cooling from a 
solidified state to the temper coldness of the atmos¬ 
phere, wherever there is any restraint upon its con¬ 
traction, is that ranging from 1,600 degrees F. to 
1,200 degrees F., or in color from a light to a dark 
cherry. 

One reason for describing the above tests in the 
manner detailed is owing to the fact of a low silicon 
mixture being used with but two 50-pound weights 
suspended to retard the contraction. Many other ex¬ 
periments were made, as will be shown further on. 

In closely watching the movements of the pointers 
of the restrained and free bars as they contract, a 
wavering, quick, forward (and often backward) mo¬ 
tion, sometimes as far as one-half degree, will be 
plainly noticed in the restrained bar, while the free 
bar has a constant steady forward movement. The 
quick, wavering motion is occasioned by the resistance 
to free contraction, which the weights offer to the bar, 
and occurs when the contraction occasionally has suffi¬ 
cient power to overcome the influence of the weights 
to stretch out the cooling iron. The fact that cast 
iron can be stretched is also often exemplified in 
heavy foundry work in the cooling of castings, exam¬ 
ples of which in every-day practice the writer will cite 
further on. 


STRETCHING CAST IRON, ETC. 


427 


A factor not to be lost sight of at this point is 
the positive manner in which the device here de¬ 
scribed verifies that there is a moment of expan¬ 
sion in molten iron cooling down to a solidified state. 
To demonstrate this by the device shown, it is neces¬ 
sary to cast one bar between fixed iron ends which 
cannot be moved apart by the strain of the expansion, 
and another bar which shall have the end at the pointer 
P free in the sand to record any expansion which may 
take place. 

Any one experimenting in this manner will find 
that the bar left free to expand will move the pointer 
to the right of zero from one to two degrees, while the 
bar cast between the iron ends or yoke will not move 
the pointer until it starts to the left, thus showing 
that iron will expand if left free to do so. 

The author wishes to state that he is of the belief 
that with such a device as shown founders will event¬ 
ually be able to utilize the expansion of metal to de¬ 
note the grade of hardness, etc., in the short period 
of one minute after the molten metal has been poured. 
There are several w^ays in which such a quick deter¬ 
mination of the grade, etc., of metals could be practi¬ 
cally applied and prove of some value to the metal¬ 
lurgical world. 

The author could detail all the tests which he has 
made to show the movements of the pointers at every 
few moments, but as what he has given is in a practi¬ 
cal sense, all that is necessary to prove the theory ad¬ 
vanced by this paper, such minute details have been 
omitted. Suffice it to say that the principles in ex¬ 
pansion, contraction and stretching presented are not 
a result of one or two experiments, but of a 


428 


METALLURGY OF CAST IRON. 


large number of tests, and that with a weight of 500 
pounds suspended at E and an iron of about 1.50 in 
silicon, .050 sulphur, he has made a difference of one- 
quarter inch in the final contraction of the free and 
restrained bars, and is of the opinion that with higher 
silicon, or a softer iron, he would be able to make the 
final stretching of the restrained bar exceed that of 
the free one over three-eighths of an inch. The size 
of pattern A is one inch by one and one-half inch, 
and three feet four inches long over all, as shown 
by the cut at A, Fig. 90, page 425. 

Returning to the subject of stretching cast iron, the 
author will cite a few instances in every-day heavy 
founding that will further assist to demonstrate the 
existence of such a quality. As one illustration of this 
fact, I refer to the making of some large Martin pump 
castings which I made in the year 1879 at the Cleve¬ 
land Rolling Mill Company’s foundry, in Cleveland. 

These were of a design requiring many large cores, 
and when the patterns were made the usual stereo¬ 
typed contraction of one-eighth inch per foot was al¬ 
lowed for the castings. I had made about four of 
these castings when I was one day called upon by 
the manager to explain to him what I had done to 
cause the castings (cope as well as nowel parts) to be 
larger than the patterns, which had caused a great 
loss in other smaller castings that would have to be 
made over in order to correspond in size to the differ¬ 
ent parts of the large pump casting. The investigation 
simply resulted in showing that the designer, drafts¬ 
man and pattern-maker were all ignorant of the quali¬ 
ties which exist in cast iron, permitting it to be stretched 
when cooling, after solidification has taken place. 


STRETCHING CAST IRON, ETC. 


429 

It is natural to inquire as to the reason for the iron 
being stretched to such a large degree in these cast¬ 
ings. The author’s, hypothesis is that owing to the 
castings being filled with large cores containing both 
slim and thick cast and wrought core rods, as soon as 
the cores became heated they and all the rods ex¬ 
panded and, by outward pressure which they exerted, 
overcame the resistance of the outer body of the green 
sand mould; and while the metal was in a fluid state, 
instead of shrinking, as is generally the case with 
heavy castings, some of it would actually flow back 
and run out over the flow-off gates. This action con¬ 
tinued until solidification took place; then stretching 
of the half molten or solidified iron came into play, 
expanding all sides of the green sand mould until the 
force of the expanding cores and their rods gave way 
to that of the outer mould’s body of metal, and the 
casting attained that point of cooling, as shown in the 
experiments illustrated with the author’s device, Fig. 
89, in which it had cooled sufficiently to overcome the in¬ 
fluence of the power most greatly exerted to stretch 
the iron, thereby exerting an expanding power at a 
time when the cooling iron was most susceptible to 
stretching, which, of course, varies according to the 
thickness of a casting, its rate of cooling, etc., to ob¬ 
tain a temperature from 1,600 degrees F. down to 
1,200 degrees F., as cited on page 426, in the stretch¬ 
ing tests with the apparatus above described. 

The case of the pump which has been cited exhibits 
a form of power, proper to be classed as expansion 
and compression resistance to contraction. We still 
have another form, which I will call heat resistance, 
and which displays its power to stretch iron by reason 


430 METALLURGY OF CAST IRON. 

of the carbon being more completely transformed to 
graphite under slow cooling. An example of this is 
an experiment which was made by a New York City 
founder some years ago. 

The feat achieved by the founder was that of casting 
a balance wheel of about 18 inches diameter, having a 
rim about two inches thick, with four to six arms only 
about one-quarter inch thick. The wheel was on ex¬ 
hibition for some time and the wonder of founders was 
how it held together. The author was informed that 
the secret lay in a heating device, so arranged as to 
keep the arms at a high temperature and to preserve 
the temperature close to that of the rim, as the latter 
was cooled off. The author would say that the feat 
was not achieved wholly by reason of extended heat, 
evolving greater graphite carbon in the arms. The 
element of stretching also assisted while keeping the 
arms hot, thus permitting the pulling power of the rim 
to extend them. 

When we consider the difference that naturally exists 
in the contraction of light and heavy bodies, so clearly 
displayed in the test cited, pages 390 and 420, of a four 
by nine and one-half by two bar, it cannot but be evi¬ 
dent that had the above wheel been left to cool off 
naturally, the arms would have pulled away from the 
rim. This founder’s achievement involves a lesson 
not to be forgotten by any interested in the founding 
or designing of machinery. 

The ignorance which prevails on the question of 
contraction is very often astonishing. It is only the 
fact that cast iron will stretch that saves many from 
having their ignorance on this subject exposed. There 
are many castings made that would not hold to- 


STRETCHING CAST IRON, ETC. 


43 i 


gether were it not for the stretching property of 
cast iron. In this case, as in all else in mechanics, 
there is a limit to abuse, and it is not infrequent 
that we find this limit passed; but when it is, the iron 
founder is almost invariably held responsible for the 
results. When the casting cracks, the designer is 
the last man upon whom there is any suspicion of 
blame, when in reality he often is the one at fault. 

This is not to be taken as relieving the founder of 
all responsibility in the question of cracked castings, 
etc. When the principles involved in the stretching 
and contraction of cast iron are understood, he can 
often, by methods of cooling and permitting freedom 
for contraction, do much to partly relieve dispropor¬ 
tionate castings of internal strains, which, if they do 
not rupture a casting before it leaves the founder’s 
door, may often do so after it has gone into use. It 
must be remembered that there is hardly a piece of 
machinery but has some part stretched, or held 
in strain, and if the latter is the case, we may often 
fear fracture or cracks, eventually causing injury to 
property and loss of life. 

Another feature to be noted in this chapter is the 
permanent expansion known for many years back to 
take place in castings subjected to heat, as is found in 
the case of Nealing Pots, Hot Blast Pipes, Grate Bars, 
etc , all involving an action that was brought proini 
nently before the public in a very valuable paper, pre¬ 
sented to the Franklin Institute by Alex. E. Outer- 
bridge, Jr., January 7th, and published by many of 
the leading trade papers during the spring of 1904. 
Repeated high or long heating can expand iron cast¬ 
ings so that they will be much larger than when first 
placed in use, or scraped. 


CHAPTER LVI. 


UTILITY OF CHILL TESTS AND METHODS 
FOR TESTING HARDNESS. 

In regard to the general utility of chill tests, some 
have believed that if a founder knew what an iron would 

chill ” in some test bars or block chills, he should be 
able to define what depth of chill any casting would 
have, no other qualities being known than that of the 
iron used and form of the casting. 

There are numerous elements which affect the depth 
of chill in a casting, other than the chilling qualities 
of the iron used, which make it impracticable to say 
just what the depth of chill in a casting will be, 
from the depth of chill in a test bar or block. All we 
can do with a test bar or chill block is to get a relative 
knowledge of the natural chilling qualities of an iron. 
To illustrate this, I will state a few principles: 

First. Any casting will show a deeper chilling by 
remaining in contact with its chill until all the metal 
in the casting has solidified or it becomes cold, than if 
the union of the casting or chill were broken before it 
had occurred. 

Second. A hot-poured iron will remain longer in 
contact with a chill than a dull-poured iron, for as 
soon as the molten metal has solidified it commences 
to contract, and hence it must be plain to any one 
that the same grade of iron, if pulled away more 


UTILITY OF CHILL TESTS. 


433 


quickly from a chill at one time than another, will 
give a different thickness of chill. 

Third. The least difference in the grade of an iron 
causes a variation in its contraction, thereby causing 
one quality of iron to pull away from a side chill more 
than another. 

Fourth. The thickness of chill used affects the 
depth of the chilling in the casting, up to the limit of 
the chill being affected, in suddenly extracting heat to 
counteract the carbon at the surface body of a casting 
being evolved into any graphitic carbon. 

Fifth. The thickness of a casting affects the depth 
of a chill. 

Sixth. Degrees of fluidity affect the chill. A hot- 
poured iron will chill deeper than a dull one. See page 

373 - 

It is shown by the above that certain conditions have 
an effect in regulating the depth of a chill in castings, 
and that it is impossible for any one to tell what the 
exact “ chill ” will be in a casting by means of a chill 
test; but where one has had considerable experience 
with the special casting and takes into consideration all 
the elements in the case, he can closely draw his own 
deductions as to what depth of chill he may expect 
in the castings. To do this we must especially consider 
the thickness of our casting in connection with the iron 
used, also whether the casting will remain in con¬ 
tact with its chill mould, or pull away from it; also 
the fluidity of the metal with which a casting is 
poured. Further information on chilling is found on 
pages 258, 502 and 513. 


434 


METALLURGY OF CAST IRON. 


In reference to testing chilled iron, Mr. Asa W. Whit¬ 
ney, in a paper on “ Chilled Iron,” before the Phila¬ 
delphia Foundrymen’s Association, January 6, 1897, 
showed that the transverse strength, as well as the 
resilience of chilled iron, is the greatest in the direction 
of the chill crystals. He also shows that “ tumbling ” 
chilled or white iron is not as effective in increasing 
the strength of iron as is the case with medium or gray 
irons, qualities cited on pages 441 and 442. 

Reliable methods for testing hardness of iron have 
long been needed. It is often as important to test the 
degree or character of hardness in castings as any 
other physical properties. There are quite a number 
of manufacturing industries of the character like chill 
roll founders, car wheel works, crushing machinery, 
die and brake shoe manufacturers, that could, had 
they but a good reliable hardness test, find it in time 
to be as important, if not often more so, than any ten¬ 
sile or transverse tests they could use. We have no 
physical test that has proven more unsatisfactory than 
that of obtaining the hardness of iron. However, 
improvements are being made as shown on pages 435 
to 438 that may meet many requirements. Many 
plans have been used to ascertain the relative hardness 
of material. One, which was popular for a time, is 
said to have been proposed by Moh, and is classed 
under three heads: (1) Any material which could be 
scratched by a finger nail, (2) that scratched by a knife 
blade, (3) and that affected by a file. After the above 
came the weighted diamond point, followed by the 
punch struck with a given weight. The diamond 
point device was used by means of weights sliding on 
a lever, and as the specimen to be tested was moved 
the weighted diamond would trace a scratch or 
leave a cut the character of which recorded the hard- 


METHODS FOR TESTING HARDNESS. 


435 


ness of the material. An apparatus was also used 
having - an obtuse-angled hardened point which would 
fall from a height upon the specimen to be tested, and 
according to the size of the indentation made the hard¬ 
ness was defined. A late method is that of testing 
hardness by means of electricity, in which a current 
passes through the specimen to be tested and through 
other standard pieces. The current necessary to pro¬ 
duce fusion is observed and compared with that of the 
normal pieces when they fuse. 

Up to about 1900 the best device we had for 
testing relative degrees in the hardness of metals is 
that of Professor Thomas Turner, who stood at the 
head of professional men in advancing knowledge on 
iron, etc. It affords the authjor much pleasure to here 
present a cut of the device, accompanied by a descrip¬ 
tion in the professor’s own language: 

My first arrangement is as follows. Fig. 91: It consists of a bal¬ 
anced and graduated beam of gun metal A working on steel knife 
edges B and counterposed by means of a large sliding weight F, 
the final adjustment being obtained by the screw G. When 
balanced, it is sensitive to 0.01 gramme at E, though such delicacy 
is not probably required. The knife edges rest upon planes in 
the support C, which is capable of rotating on a steel pivot con¬ 
nected with the rod D. The diamond is mounted in a brass tube, 
having a milled head which is fixed by means of a screw at E. 
The specimen to be tested, which often takes the form shown, J, 
is supported by a wooden block K. The weight H is arranged 
so that each division on the graduated scale shall correspond to 
a pressure of a gramme at the diamond point. Thus, at division 
12, we have a pressure of 12 grammes on the diamond. Three 
extra weights, I, are used when necessary. They are each of 
the same weight as H. Hence, with one weight, scale division 
10 corresponds to 10 grammes on the diamond, with two weights 
10 corresponds to 20 grammes, with three weights to 30 grammes, 
anc^ with four weights to 40 grammes, the other scale divisions 


metallurgy of cast iron. 


43 6 


being read in an exactly similar manner. It will be noticed that 
the specimen is stationary while the diamond is moved, thus 
differing from the scler- 
ometer as applied to min¬ 
erals ; the method of sup¬ 
porting the beam and of 
applying the weight is 
also different. In ordi¬ 
nary experiments, where 
considerable weights are 
applied, the diamond 
may be moved by the 
finger, and as the appa¬ 
ratus is very steady in its 
actions, with a little care 
this gives very concord¬ 
ant results. For more del¬ 
icate observations with 
smaller weights, the dia¬ 
mond may be drawn by 
means of a horizontal 
string running over a 
small pulley. The sur¬ 
face used is prepared 
roughly in the ordinary 
way by chipping, filing, 
etc., and then with a 
smooth file; it is finished 
with emery paper, using 
at last the finest variety, 
or flour emery, and oil, 
according to the material. 


A. Beam. 

B. Knife-edge. 

C. Rotating Support. 

D. Steel Rod and Pivot. 

E. Diamond. 

F. Sliding Weight. 

G. Adjusting Screw. 

H. Sliding Weight. 

I. Extra Weights. 

J. Test Piece. 

K. Wooden Support. 



FIG. 91. 





































































































Methods for testing hardness. 


437 


It should be finished all one way, so as not to leave small, irregu¬ 
lar scratches, and should be as smooth and bright as possible. 
As a rule, an experienced workman should not take more than 
half an hour in preparing such a specimen, although occasionally 
a hard material will take longer. If the surface tested be rough, 
the results are erroneous, being generally higher than with a 
good surface. It can, however, be told at once on inspection 
whether a surface is suitable for the purpose. If any doubt should 
exist, another smooth face must be prepared and the experiment 
continued until uniform results are obtained. 

The following Table prepared by Professor Turner 
clearly presents the utility of his device and illustrates 
the thorough manner in which he completed his work. 
It has been thought by some inexperienced founders 
that there is no limit to silicon softening iron, but this 
is strongly refuted by the following Table 87 and sus¬ 
tains the author in statements made in other writings 
to the effect that silicon can harden as well as soften 
iron: 


TABLE 87. —INFLUENCE OF SILICON ON THE HARDNESS AND TENACITY 

OF CAST IRON. 


No. 

Silicon per cent. 

Tensile Strength. 

Hardness. 

1. 

0.19 

10.14 tons. 

72 

2. 

o -45 

12.31 “ 

52 

3 - 

0.96 

12.72 “ 

42 

4 - 

1.96 

15-70 “ 

22 

5 - 

2-51 

14.62 “ 

22 

6. 

2.96 

12.23 “ 

22 

' 7 - 

3-92 

11.28 “ 

27 

8. 

4-75 

10.16 “ 

32 

9 - 

7-37 

5-34 “ 

42 

10. 

9.80 

4-75 “ 

57 


WORKING QUALITIES. 

1. —Very hard indeed. 

2. —Very hard, though not so hard as No. i. 

3. —Hard, though softer than No. 2. 

4. —Good, sound, ordinary, soft-cutting iron, of excellent quality. 

5. —Rather harder than No. 4. 

6. —Like No. 4. 

7. —Like No. 6, but rather harder. 

8. —Rather harder than No. 7, though not unusually hard. 

9. —Still harder, cutting very like No. 10. 

10.—Hard-cutting iron, though still softer than No. 1. 
















4 3& 


METALLURGY OF CAST IRON. 


There have been several other machines designed for 

testing hardness since Professor Turner perfected his 
machine. One is a design by Mr. W. J. Keep, being an 
improvement on one designed by the late Mr. C. A. 
Bauer, M. E., and which was presented at the New 
York meeting of the American Society of Mechanical 
Engineers, December, 1900, and also described in the 
American Machinist, February 28, 1901. Fig. 53 shows 
an ordinary drill press which was fitted up by the author 
to test the hardness of metals, and which worked very 
satisfactorily for the class of testing it was intended 
for. A full description of this machine is given on 
pages 234 and 238. 


CHAPTER LVII. 


UTILITY OF TRANSVERSE, CRUSHING, 
IMPACT AND SHOCK TESTS. 

The tests called for in our engineering and other 
scientific text books include transverse, tensile and 
crushing strength, a few giving impact. Of all these, 
none can surpass in value for general use the trans¬ 
verse test, with its accompaniment of “ deflection ’' 
for foundry practice, simply because castings arc 
chiefly subjected to such strains. The utility of ten¬ 
sile tests will be found discussed on page 449. The 
quality of cast iron to withstand crushing loads is 
also one often of much importance to the engineer 
and founder. The values found by the author from 
which the relation between crushing and tensile 
strength may be deduced lead him to affirm that 
the elements constituting a test in transverse, de¬ 
flection and chill are, for general purposes, largely a 
good index as to the crushing strength. An iron 
having a high transverse strength combined with 
small deflection should prove the best to withstand 
crushing loads. 

Impact tests on the side of bars are of little prac¬ 
tical value in assisting to determine what castings can 
stand in shocks or blows.* If there is any form of 
tests with test bars, to demonstrate the power of iron 
to withstand shocks or blows, there is much more 

* This has reference to striking test bars until they break, and 
not to such tests as are outlined on the next two pages. 



440 


METALLURGY OF CAST IRON. 


practical sense exhibited in looking to high transverse 
and deflection combined with a low contraction, than 
to impact blows on the side of a test bar. A prac¬ 
tical way to apply an impact test is to the castings 
themselves. The car wheel men teach a lesson in 
this respect. Here we find that some select from 
a large stock one wheel out of every hundred, and if 
by dropping a 140-pound weight on the hubs of the 
sample wheels from a height of 12 feet the sample 
wheels stand five blows each, all the other wheels are 
then accepted, providing they have stood the thermal 
test described on page 443, and which shows, in connec¬ 
tion with the above impact tests, the absurdity of think¬ 
ing to be guided by impact blows on the side of test bars. 

The power of castings to withstand shocks or blows 
is often far more affected by their proportion or design 
than by the quality of iron composing them. There 
is altogether too much indifference exhibited by de¬ 
signers of machinery in proportioning castings so as to 
have the least possible internal contraction strain in 
them. Some designers seem to ignore wholly the fact 
that a light body will contract more than a heavy one. 
Many castings have been made, the iron in which 
would test all right as far as test bars were concerned, 
but subjecting them to shocks or blows, would imply 
that the iron was not of the right character. This again 
illustrates the impracticability of some impact tests on 
bars and shows that a weak, high-contraction iron can' 
often be of much more value in a well-proportioned 
casting than the reverse kind of iron in an ill-propor¬ 
tioned one. 

A. E. Outerbridge’s shock tests form an interesting 
study in this connection. In these tests, Mr. Outer- 


TRANSVERSE, CRUSHING, IMPACT AND SHOCK TESTS. 441 

bridge found that shocks or light blows delivered on 
test bars increased their strength, and therefore illus¬ 
trate the benefits to be derived by the gradual in¬ 
crease of severity in shocks to strengthen castings, 
such as guns which are subjected to great strains from 
sudden jars or blows to the metal comprising their 
bodies. They also show wherein many castings long 
in use can have their durability increased, becoming 
really better than new castings. 

These tests were made by means of twelve compan¬ 
ion test bars that had been moulded in one flask and 
cast with the same gate and ladle of iron. Six of 
these test bars were subjected to shocks by reason of 
tumbling in a “tumbling barrel,” and in other 
cases the shocks were transmitted to the test bars by 
means of tapping them on their ends with a hand 
hammer. The six bars not receiving shocks in any 
manner were invariably found the weakest. The bars 
receiving the shocks were shown by a large number of 
tests made by Mr. Outerbridge to have been increased 
in strength from ten to fifteen per cent, and the larg¬ 
est gain, in a few instances, was found to be about 19 
per cent. The bars tested were one and one-eighth 
inch round, and also square bars of one inch section, 
both fifteen inches long. Mr. Outerbridge says the 
crucial test was in subjecting six bars to 3,000 taps 
each with a hand hammer upon one end only of each 
bar. The tumbling barrel process of giving shocks to 
bars continued for about four hours. The publication 
of Mr. Outerbridge’s discoveries by trade papers has 
led many founders to experiment in testing his deduc¬ 
tions, and all have found them to be true, some even 
exceeding the strength obtained by Mr. Outerbridge. 


442 


METALLURGY OF CAST IRON. 


One case which has come to the writer’s knowledge 
showed a gain of 29 per cent, by reason of tumbling 
test bars. For results with chilled bars, see page 434. 

Mr. Outerbridge was led to demonstrate that shocks 
could increase the strength of cast iron by first observ¬ 
ing that chilled car wheels rarely cracked in ordinary 
service, after having been used for a considerable 
length of time. He says if they did not crack when 
comparatively new, they usually lasted until worn out 
or condemned for other causes. Mr. Outerbridge 
found that, up to the point of the shock relieving the 
internal strains by permitting the individual metallic 
particles to re-arrange themselves and assume a new 
condition of molecular equilibrium, any further shock 
did not increase the strength. He does not say this 
would injure it, and, in speaking of a few practical de¬ 
ductions for universal application to be drawn from 
his tests and observation, he says: “ Castings such as 
hammer frames, housings for rolls, cast iron mortars 
or guns, which are to be subjected to severe blows or 
strains in actual use, should never be tested to any¬ 
thing approaching the severity of intended service.” 
Mr. Outerbridge’s discovery is a valuable one, and can 
find practical application in many ways, especially in 
showing the light-work founder that “ tumbling ” cast¬ 
ings is beneficial; but that it is best, when practical, 
where there are any fears of castings being broken, to 
start slowly and gradually increase the speed to the 
limit generally practiced when “tumbling.”* 

* The paper giving all the tests, etc., was originally presented 
at the meeting of the American Institute of Mining Engineers, in 
Pittsburg, Pa., February, 1S96, and can be found in its proceed¬ 
ings of that year. 



THERMAL TESTS FOR CAR WHEELS. 


443 


METHODS FOR TESTING CAR WHEELS. 

• 

The Master Car Builders’ Association requires that 
wheels should run for a period of forty-eight months 
in regular service. Before they are removed from the 
foundry they are subjected to a thermal and drop test, 
for which purpose twc wheels are selected by an in¬ 
spector from every lot of one hundred. We cannot bet¬ 
ter describe the methods of such testing than by an 
extract of Mr. G. W. Beebe’s paper in which he cited 
the C. B. & Q. Ry. testing specifications, etc., before 
the Western Railway Club, and published in the Iron 
Trade Review of October 2, 1900. 

“ In making a thermal test, the test wheel (see Fig. 
92) must be laid down in the sand and a channelway 
i }6 inches wide and 4 inches deep moulded with green 
sand around the wheel. The clean tread of the wheel 
should form'one side of the channelway and the clear 
flange the bottom. (It will be noted that the width of 
the channelway is equal to the height of the flange, 
namely i}& inches.) The channelway must be filled 
to the top with molten cast iron, which should be 
poured with two ladles directly into the channelway. 
The molten iron must be taken from the big ladle 
directly after a tap for pouring the wheels has been 
drawn from the cupola. The channelway must be 
filled with the molten iron in no greater time than one 
minute after the iron has been taken from the big ladle. 
No puddling or cooling of the iron will be allowed. 
If the molten iron boils in the ladles they must be 
refilled until all indications of boiling cease, before the 
channelway is filled. The time when the pouring ceases 
must be noted, and two minutes later an examination 


444 


METALLURGY OF CAST IRON. 


made, and if the wheel is found cracked in the plates 
or through the thread the wheels represented by the 
test wheel will be rejected. Wheels that are wet or 
have been exposed to the frost may be warmed suffi¬ 
ciently to dry or remove frost before testing. At the 
option of the manufacturer, if the test wheel fails 
under this thermal test, a second wheel showing 
the next lower contraction size to the wheel which 



failed, and cast on the same date as the rejected wheel, 
may be selected by the inspector and tested. If the 
second wheel stands the thermal test, all wheels of the 
same, and all lower contraction sizes, may be accepted; 
while the wheels of the same and higher contraction 
as the first wheel must be rejected.” 

“ The contraction allowed on a cast iron wheel is ^ 
inch — % inch above and % inch below the mean cir¬ 
cumference, divided into four tape sizes of }£ inch. 
The tape No. i, or highest contraction, represents the 
weaker wheels, conditions being normal. The inspec¬ 
tor being aware of this, almost invariably selects tape 

























THERMAL TESTS, ETC., FOR CAR WHEELS. 


445 


No. i, or highest contraction number, for the test. If 
tape No. i fails when in the thermal test, reject such, 
and allow the inspector to select one of tape No. 2, or 
next lower contraction number; and if the second 
wheel fails reject all of the wheels represented. Pro¬ 
viding, however, the. second wheel stands the thermal 
test, it seems hardly fair to the manufacturer to con¬ 
demn the second and lower shrinkage numbers, the 
inspector being satisfied by the test on the second tape 
sizes that they are sufficiently strong and are hard 
enough to give the wear. An inspector should make 
a study of iron, so that he can readily designate at a 
glance whether the first wheel failing could be attrib¬ 
uted to bad iron or abnormal conditions in the pitting 
or handling of the rejected wheel. A wheel can be 
made of a hard close grain iron that will stand the 
drop test or concussion in service, but if subjected to 
a severe and continued brake application is liable, as 
boys say, “ to go up in smoke.” A gritty, hard chill 
will not make the mileage that a tough chilled wheel 
will. A gritty chill will shell out quicker than a tough 
one, because it will not stand the heat that is caused by 
severe brake application. Good white iron is tough, as 
well as being hard enough. There is as great a differ¬ 
ence in the quality of white iron as there is in gray 
iron; bad white iron has a large proportion of sulphur. 
I believe the steel-tired wheel proves that the tough¬ 
ness give the wear. I have not seen or heard of a 
steel-tired wheel shelling out. I have heard some rail¬ 
road men say that when they can cut the chill of a wheel 
with a chisel, the wheel will not make good mileage. 
If this is the case the steel wheel could not make the 
mileage that is claimed for it, because the steel-tired 


446 


METALLURGY OF CAST IRON. 


wheel is turned before being put into service, and it 
certainly must be soft in order that it can be turned. 
These hard, gritty wheels will fail in the thermal test, 
or by severe brake application. Regarding the depth 
of chill, it should not exceed ^ inch in the throat, or 
15-16 inch in the center of the tread. The minimum 
should not be less than inch in the throat, or inch 
in the center of the tread. Assuming that we have the 
maximum depth of chill—15-16 inch — we get the 
blending of the white iron through the entire tread, 
and begin to crowd the danger line and gain nothing, 
as the highly chilled wheel will shell out and become 
capable of sliding more readily than a medium chilled 
wheel. In breaking up three hundred defective wheels 
that were removed on account of shelled spots, 95 per 
cent, showed a high chill. 

“ The design of a pattern is one of the essential factors 
in the manufacture of the cast wheel, other than the 
thickness of flange, shape of hub, and tread. The 
designing of the pattern should be left to the discre¬ 
tion of the manufacturer. A large percentage of 
wheels that fail in the brackets can be ascribed to a 
poorly designed pattern; too light brackets will crack 
because they cool more rapidly than the plate of the 
wheel, which would cause a strain on them; too heavy 
a bracket will throw the strain on the plates, causing 
the plates to crack. For those who are not familiar 
with the drop test used in testing wheels, Fig. 93 
gives an illustration of the Barr drop, and Fig. 94 the 
M. C. B. drop. It will be noted that the hammer of 
the Barr drop strikes the single plate of the wheel (see 
letter A on Fig. 93). The hammer of the M. C. B. 
drop strikes the hub of the wheel (see letter A on Fig. 


DROP TESTS, ETC., FOR CAR WHEELS. 


447 


94). A wheel rarely fails in service in the hub, double 
plates, or at the intersection of the plates (see letters 
A, B, and C on Fig. 94). If a crack does occur at these 
points it does not necessarily cause the wheel to become 
dangerous. If a crack occurs in the single plate (see 
letter A on Fig. 93), we then have a dangerous wheel, 
and it will not run long before giving way entirely. 
It will also be noted that wheels tested under the M. 



FIG. 93. —BARR DROP FIG. 94. —M. C. B. DROP 

TESTING MACHINE. TESTING MACHINE. 


C. B. drop are placed flange downward on an anvil 
block, having three supports for the flange of the wheel 
to rest upon. The hammer strikes the central part or 
hub and the whole of the wheel resists the concussion, 
while the wheels tested under the Barr drop are placed 
flange downward on a flat surface anvil block and the 
wheel receives the concussion at one point only. The 
Chicago, Burlington & Quincy specifications require 
wheels tested under the Barr drop to stand fifty blows 
























































































448 


METALLURGY OF CAST IRON. 


without breaking out a piece. The Pennsylvania Rail¬ 
road specifications, I believe, require wheels tested to 
stand twelve blows under the M. C. B. drop without 
breaking out a piece. It would seem fair to assume 
that the Barr drop would find the weak or dangerous 
part of the wheel more readily than the M. C. B. drop. 
The treatment and handling of the hot wheel has 
nearly as much to do with the strength as has the 
material used. Cold iron will produce seams in the 
tread and internal strains, because the molten iron sets 
in the mould as fast as it is poured. Hot iron, with 
slow and uneven pouring, produces sweat in the throat, 
uneven chill, and internal strains; delay in getting the 
hot wheel into the pit after being shaken out of the 
mould will also produce strains in the wheel by uneven 
contraction. Wheels should be poured with fairly hot 
irons and fast. The limit of time in pouring a 33-inch 
wheel should not exceed twelve seconds. Table 88 
gives the analysis of a number of wheels tested under 
the Barr drop, and in the thermal test:” 


TABLE 88. 



Wheels 
that failed 
in thermal 
test. 

Wheels 
that stood 
thermal 
test. 

Wheels 
that failed 
under 50 
blows, Barr 
drop. 

Wheels 
that stood 
50 blows 
and over, 
Barr drop. 

• 

Max. 

Min. 

Max. 

Min. 

Max. 

Min. 

Max. 

Min. 

Total carbon . 

3 - 9 1 

3-63 

3-90 

3-38 

3-87 

3-42 

3-93 

3-49 

Graphitic carbon .. 

3.02 

2.92 

2.98 

2.71 

3 -19 

2.90 

3.02 

2.90 

Combined carbon. 

.89 

• 7 i 

.92 

.67 

.68 

•52 

• 9 i 

•59 

Sulphur . 

.090 

.042 

.10 

.080 

.080 

.020 

.070 

•05 

Mangane.se. 

.60 

•49 

•58 

.48 

.62 

.40 

• 72 

•47 

Silicon. 

.82 

•50 

• 9 i 

•50 

•97 

.67 

1.10 

.68 

Phosphorus. 

.48 

•39 

•52 

.26 

•58 

•30 

•53 

.28 


A part of the wheels failing under these tests cannot be ascribed to the 
composition. 

























































































CHAPTER LVIII. 


ACHIEVING UNIFORM RECORDS, AND { 
UTILITY OF TENSILE TESTS. 

Any research to discover uniformity between tensile 
and transverse tests, up to about 1895, shows that one 
plan of testing gave very different results than some 
others, and only bewilders instead of assuring an inves¬ 
tigator that he has obtained any knowledge of the 
iron’s true strength. There is no reason why the same 
iron should show such erratic records as have been 
evinced up to 1895, between tensile and transverse 
tests, that can be charged to the iron proper. 

When evils due to casting test bars flat are consid¬ 
ered as proven in Chapter LXV., one great cause 
for the wide difference recorded in the past is clearly 
displayed. How is it possible to expect other than 
erratic and unreliable records, when the fact of a flat- 
cast one-inch-area test bar being 200 to 400 pounds 
stronger on one side than the other is considered? 
Any one giving thought to this subject cannot but 
perceive the unreliable records which casting flat must 
cause, and become convinced that the plan of casting 
on end far surpasses past methods, in order to insure 
uniformity between tensile and transverse or either 
tests taken from bars cast off from the same ladle. 

For foundry and engineering purposes it can be said 
that tensile tests are often valuable for comparative 


45 ° 


METALLURGY OF CAST IRON. 


tests. With a standard length of a bar for transverse 
strength and one of equal area for tensile testing of 
the round form, not exceeding i ^ inches diameter and 
cast by the system advocated by the author, a study 
on comparisons leads him to say that transverse and 
tensile tests will be found to bear a very close relation 
to each other, and prove that the tensile test may, for 
some purposes, be of as much benefit for a comparative 
test as are transverse tests. 

When test bars exceed one and one=half inch diam= 
eter the transverse and tensile strength tests com¬ 
mence to diverge radically in opposite directions, the 
tensile strength decreasing in strength per square inch 
while the transverse increases, a point more fully 
explained in Chapter LXX., page 571. With bars 
under 1 % inches diameter the tensile strength will 
closely average ten times the strength of transverse 
tests, in like areas. 

' * 

One difficulty in obtaining tensile strength often 

lies in the method of obtaining them. Some machines 
can take such a rigid grip as to exert a strain on some 
portion of the specimen, instead of permitting the test 
bar to adjust itself centrally so as to insure a uniform 
pull over its entire breaking area. Cast iron requires 
different treatment to insure a uniform pull than steel 
or wrought iron, but with the use of specially designed 
test bars permitting a good area for gripping, or 
having shoulders cast on each end with holes in them 
at cross angles to each end whereby pins can be in¬ 
serted to allow a specimen to adjust itself centrally 
to its load, very accurate tests may be obtained. Ten¬ 
sile, like transverse tests, can only be comparative in 
the same area or size of test bars, see page 528. 


CHAPTER LIX. 


CONTRACTION vs. STRENGTH OF CAST 

IRON.* 

As to indicating unfitness of a test bar to record 
contraction of cast iron, when it has been proved 
of no value to record strength, experiments which 
the author has often conducted have demonstrated that 
the percentage of combined or graphitic carbon in a 
light casting or small test bar can often be regulated as 
much by varying conditions in the physical qualities of 
the mould as by varying percentages in the elements 
of sulphur, silicon, manganese, phosphorus, etc., gen¬ 
erally contained in foundry pig metal. We will first 
consider the physical qualities which can affect the 
strength of an iron, according to the size of a casting 
or test bar, and which is chiefly (aside from the “ iron ”) 
.dependent upon the state of the carbon, whether it is 
in the combined or graphitic form. See page 206. 

Believing from the results of previous experiments and 
every-day experience that if the corners and the cen¬ 
tral portion of square test bars were analyzed, a differ¬ 
ence would be found existing in their percentage of 
combined or graphitic carbon; also that the combined 
carbon would be less in a one-inch square bar than in 
a one-half-inch square bar, both poured from the 

* Extract from a paper read before the Foundrymen’s Associa¬ 
tion, Philadelphia, Pa., September 4. 1895. 



45 2 


METALLURGY OF CAST IRON. 


# 

same iron and gate, I forwarded the specimens of 
which the analyses are herewith given to the late C. A. 
Bauer, M. E., general manager of Warder, Bushnell 
& Glessner Co., Springfield, O., who had his son, 
Charles L. Bauer, a chemist, make the determinations 
shown in the following paragraphs: 

The specimens were one-half inch square, one inch 
square and one and one-eighth inch round bars, belong¬ 
ing respectively to light machinery and chill roll iron 
tests, which were among those reported in my paper 
before the Western Foundrymen’s Association, October 
18, 1894, seen on pages 461 and 464. Paragraph No. 1 
gives the combined carbon at the corners and center sur¬ 
face of the fracture of the one-inch square bars in the 
chill roll and light machinery mixtures. 

Paragraph No. 2 is a report of the sulphur contents 
of the center of the bars shown in paragraph 1 and 
also that of the one-half inch square and one and one- 
eighth inch round bars shown in paragraph 3, which 
were poured with the same gate and iron as those 
in paragraph 1. 

Paragraph No. 3 shows the difference in combined 
carbon existing in the center of the one-half inch 
square, one inch square and one and one-eighth inch 
round bars described in paragraphs Nos. 1 and 2. 

Determination No. 1.—Combined carbon in chill 
roll iron: At the corners, 1.55 per cent., at the center 
of the fracture, 1.416 per cent., or .134 per cent, more 
combined carbon in the corners than in the middle of 
the test bars. In light machinery iron: At the cor¬ 
ners, .72 per cent.; at the center, .65 per cent.; or .07 
per cent, more combined carbon in the corners than in 
the center of the fracture. 


CONTRACTION VS. STRENGTH OF CAST IRON. 453 

Determination No. 2.—Sulphur in chill roll iron: 
At the center of fracture in one-half inch square, .046 
per cent. ; one inch square, .044 per cent. ; one and one- 
eighth inch round, .046 per cent. In light machinery 
iron: At the center of fracture in one-half inch 
square bar, .0819 per cent. ; one inch square, .079 per 
cent.; one and one-eighth round, .0825 per cent. Mr. 
Bauer writes that the difference in sulphur at the cen¬ 
ter and the corners of the different bars is not percep¬ 
tible. 

Determination No. 3. —Combined carbon in chill 
roll iron: In one-half inch square, 2.700 per cent.; 
one inch square, 1.416 per cent.; one and one-eighth 
inch round, 1.250 per cent. Difference in the extreme 
of the combined carbon in the one-half inch square 
and one and one-eighth inch round bar, 1.450 per 
cent. In light machinery iron: In one-half inch 
square, .854 per cent. ; one-inch square, .650 per cent. ; 
one and one-eighth inch round,. 704 per cent. Difference 
in extremes, .150 per cent, of the combined carbon in 
the one-half inch and one and one-eighth inch round 
test bars at their center of fracture. The silicon in 
the light machinery is 1.83 per cent. ; in the chill roll, 
. 71 per cent. 

The percentage of combined carbon and “ iron ” in a 

casting, etc., chiefly controls the strength of the iron 
and also its contraction. The percentages of sulphur, 
silicon, manganese and phosphorus in cast iron are but 
factors in connection with the time it takes a test bar 
or casting to solidify and become cold, determining the 
degree to which the carbon takes the combined form. 

The above analyses plainly prove that a slight differ¬ 
ence in the fluidity of metal, or dampness in the 


454 


Metallurgy of cast iron. 


“temper” of sands, as commonly used in ordinary 
foundry practice, can cause a radical difference in the 
percentage of combined carbon, in the same size and 
form of small castings or test bars from the same 
mixture of iron, poured out of the same ladle. The 
determinations Nos. i, 2, and 3 also indicate the neces¬ 
sity of adopting, for physical tests, the size and form 
of test bar least liable to irregularities in the combined 
carbon composing its shell or outer body, caused by 
varying conditions in the “temper” of sands and 
fluidity of metals, etc. As degrees in the strength of 
iron can be affected by the “temper” of sand and 
fluidity of metal at the moment it is poured, so can 
contraction records be likewise affected, making them 
deceptive. Experiments which I have conducted to 
discover if the same conditions which give erratic re¬ 
sults in strength records would not do likewise in con¬ 
traction, have only the more confirmed me in the 
advocacy of bars over one square inch in area, wherever 
one desires to be wholly or partially guided by phys¬ 
ical tests. 

To learn whether differences in the temper of sands 

could cause changes in the length of contraction in small 
bars of the same size, cast in the same mould with the 
same iron, out of the same ladle, and at the same mo¬ 
ment, I took three patterns inch square and 12 inches 
long, and cast two of them between yokes and a third 
bar in a divided chill to form two sides and bottom of 
the mould, the fourth side being formed by the sand 
of the cope. The two bars cast between yokes had 
drier sand for one than for the other. The dampest 
sand was not so damp but that a sound casting could be 
produced, and the two sands differed no more than can 


CONTRACTION VS. STRENGTH OF CAST IRON. 455 

often be found between the “ temper ” of sands in one 
shop. All three bars were placed equidistant in the 
mould and gated by means of two upright “ sprues ” 
which led down to a runner in the cope extending over 
the three bars in the center, insuring the filling of the 
three moulds at the same time with the same hand ladle 
of iron. The test bars formed in the chill and dampest 
sand showed a greater contraction than the ones 
enclosed in the driest sand. I have conducted quite a 
number of these tests and always found in them the 
same results, those cast in the chill showing the greater 
contraction. In several cases, the extremes of one 
flask gave a full one-sixteenth inch difference in 
the contraction of the three bars. In the extremes be¬ 
tween the “ temper” of the wetter and drier sand, I 
have found a difference of fully one thirty-second part 
of an inch to exist in the contraction of two one-half 
inch bars poured from the same hand ladle at the same 
moment, thereby proving that a test bar as small as 
one-half inch square or round is altogether too sensi¬ 
tive to variation in the “ temper ” of moulding sand to 
be relied upon to afford any true knowledge of the 
natural contraction of an iron. 

1 To discover what effect, if any, degre3S in dampness 

or “temper” of sand have on a round bar cast on 
end, I took a pattern one and one-eighth inch in 
diameter and made a dry sand mould, using a piece 
of six-inch gas pipe to mould it in, leaving both ends 
open. After this little mould was dried in an oven, 
it was set on end upon a planed plate and the distance 
equally divided between two empty gas pipes. Each 
of these two latter pipes was then rammed up with 
“ green sand ” of a different temper. Each test bar 


45 6 


METALLURGY OF CAST IRON. 


had a projection cast on the upper end exactly two feet 
from the bottom of the mould, which was formed by 
the bottom plate to measure contraction by. The three 
bars were poured by one ‘runner in the center of the 
three moulds, the iron dropping from the top. I made 
these three bars two feet long, so as to give a greater 
length than was in the one foot long by one-half 
inch square bars, -to better detect any difference that 
might exist in the contraction of the bars due to 
variation in the “ temper ” of the sand. When these 
bars were measured, no difference could be found in 
their contraction — a further proof of the necessity 
of using a bar larger than one-half inch square or 
round to show the true contraction of an iron. I also 
made tests with one and one-eighth inch round bars 
cast flat, but did not find that the radical variation 
which existed in the “ temper ” of the sand made any 
difference in the length of their contraction. Previous 
to these tests, I also made some in our foundry in the 
presence of E. Duque Estrada, M. E., of Pittsburg, a 
member of the American Society of Mechanical 
Engineers’ Testing Committee, to learn whether 
degrees in fluidity of iron would affect the contraction 
of large-sized test bars or thick castings. To test this 
point, two bars two inches square and forty-eight 
inches long were moulded together in the same mould. 
One was poured with the metal as “ hot ” as could be 
obtained from the cupola, and the other with the same 
ladle cooled down to pour the metal as “ dull " as pos¬ 
sible and still obtain a full-run bar. Two sets of these 
experiments were made, but no difference was found 
in their contraction. The fact of there being no 
visible difference in the contraction of the two-inch 


CONTRACTION VS. STRENGTH OF CAST IRON. 457 

square bars cast flat, also the one and one-eighth inch 
round bar cast flat and on end, was dueto the body of 
the test bars being sufficiently massive to overcome 
any tendency which variations in the fluidity of metal 
or dampness of the sand could exert in causing a 
difference in the combined carbon. With large-sized 
test bars, properly cast, having no corners to be af¬ 
fected by the “ temper ” of sands and fluidity of metal, 
contrary to the conditions seen in a square or small 
test bar, we are justified in placing the utmost con¬ 
fidence in the record which they may present. And 
were it not that in accepting castings there is gen¬ 
erally a large margin permitting the founder to often 
greatly disregard obtaining the best possible physical 
properties of the iron in his castings, the error of 
using bars as small as one-half inch square or below 
one square inch area would have been clearly demon¬ 
strated long before this. (See pages 454, 467, 484, 511 
and 573.) 


CHAPTER LX. 


COMPARISONS OF STRENGTH IN SPE¬ 
CIALTY MIXTURES.* 

This chapter is a revised extract from a report of the 

author’s labors as a member of the Western Foundry- 
men’s Association Testing- Committee, and presents a 
series taken from about one hundred tests which 
he personally obtained, of irons such as are used for gun 
metal, chill rolls, car wheels, heavy machinery, 
light machinery, stove plates and sash weights, a list 
which can be seen to cover very nearly all mixtures 
or “grades” necessary to cast iron founding. 

Each founder in casting a set of these test bars from 
the patterns which the author furnished made three one- 
half inch square, three one inch square, three one and 
one-eighth inch in the # rough, and three one and one- 
eighth inch turned. These one and one-eighth inch 
round bars in the rough and turned are of an area as 
nearly equal to one square inch as it is practical to make 
them. The turned bars were cast with a swell on so 
as to measure about one and five-eighth inches in 
diameter for about four inches of their length in the 
center. This swell was turned down until the bars 
measured close to the size of their companion, one and 
one-eighth rough bars. The comparison between 

* Read at the meeting of the Western Foundrymen’s Associa¬ 
tion, at Chicago, Wednesday evening, Oct. 24, 1S94. 



STRENGTH IN SPECIALTY MIXTURES. 


459 


the rough round and the turned bar enables .us to 
perceive the difference that may exist between the 
strength of the iron with its surface affected by the 
walls of a green sand mould and that of iron having 
its rough surface turned off. 

It was first planned to have all these test bars cast 
on end, so as to afford the most favorable conditions 
to insure solid bars, etc., but in starting with car 
wheel mixtures, difficulty was found in getting the 
half-inch square test bars to “run,” and as there 
were other strong irons I desired tests from, I had, on 
account of the one-half bars, to change the plan of 
casting and had all bars cast flat. The three test bars 
from each of the four sizes were cast all in one flask, 
poured from the same gate, and out of the same ladle. 

These test bars were cast by some of the most 
prominent foundry specialists in this country. They 
are not a crucible melt of estimated mixtures or of a 
special heat, but are taken from “regular heats” 
“run” for making castings in the specialties herein 
mentioned, therefore represent the strength of the 
actual metal used in actual practice for the manufacture 
of the castings outlined as far as is practical with bars 
cast flat.* A complete chemical analysis of the various 
mixtures obtained in the tests shown in this Chapter 
can be seen on page 299. The analyses were all taken 
from the rough bars shown in the respective Tables. 

The micrometer measurements given in the follow¬ 
ing tables are the average of dimensions taken from 
the four sides of the square and round bars and hence 
give the size of the test specimen in the thousandth 
part of an inch. The common rule measurements 
give the size as closely as it is practical to roughly 

* Views of the fractures of these various irons are seen in Figs. 
95 to 102, at the close of this chapter. 



460 


METALLURGY OF CAST IRON. 


state the dimensions. All the bars were cast 15 inches 
long and in breaking them for transverse strength 
they rested on pointed supports, 12 inches centers. 
The last two columns in the Tables give the computed 
relative strength. The outside column is used only 
for the half-inch square bars, so as to illustrate two 
methods of figuring, and is obtained by multiplying 
the breaking load by eight, a method advanced by 
some, for one-half-inch bars.* The inner is obtained 
by the rules shown in Chapter LXI., page 476. The 
area of a bar 1.1284 inch in diameter is equal to the 
area of one inch square; by keeping this in mind the 
figures in the micrometer columns can have their 
relation to a square inch readily defined. 


TABLE 89. —TRANSVERSE TESTS OF GUN METAL. 


No. Test. 

Common rule 
measure¬ 
ment. 

Microm’t’r 

measure¬ 

ment. 

Deflec¬ 

tion. 

Broke at 
in 

pounds. 

Strength per 
square 
inch 

in pounds. 

1 

2 

Rough bars. 

% in. square. 

ti tl 

.491 in. 
.501 “ 

.120 in. 

.115 “ 

376 

420 

1,560 3,008 

1,673 3,360 

3 

4 

5 

Planed bars. 

V 2 in. square. 

it 4i 

(1 l< 

.491 in. 
•495 “ 
•494 “ 

.250 in. 
.270 “ 

.200 “ 

384 

360 

316 

U 593 3,072 
1,469 2,880 
1,295 2,582 

6 

7 

8 

Rough bars. 

I in. square. 

<i ii 

II it 

1 002 in. 

996 “ 
1044 “ 

.090 in. 

.08 j “ 

.005 “ 

3.500 

3 . 38 o 

3.423 

3,486 . 

3 , 4 oo . 

3.145 . 

9 

10 

11 

Planed bars. 

1 in. square. 

it tt 

t< it 

1.007 in. 
1.005 “ 
1.005 “ 

.130 in. 
.120 “ 

.110 “ 

3 d 40 

3,095 

3,072 

3,096 . 

3/ 64 . 

3,042 . 

12 

Rough bar. 

i l /s in diam. 

1 132 in. 

.125 in. 

3 , 7 o 8 

3.6S6 . 

13 

Turned bar. 

1*4 in- diam. 

1.139 in. 

.150 in. 

3,-20 

3,258 . 


Test bars, Table 44, were furnished by Builders’ Iron Foundry, Providence, R. 
I. Tested by Thomas D. West, at the works of the T. D. West Foundry Co , 
Sharpsville, Pa., Sept. 18th, 1894. Witnesses, Geo. H. Boyd andG. M. Mcllvain. 


The first series of tests we will present is that re¬ 
cording the strongest mixture, seen in Table 89 •, the 

* By a study of Chapter LXI., it will be seen that the inner column referred 
to above is obtained by a rule that cannot be recommended for %inch bars; 
and while that used for the outside column is preferable, it would be still 
more satisfactory if it were known that the %-inch bars did never vary from 
the size of their pattern— something which it is not practical to expect 

































































STRENGTH IN SPECIALTY MIXTURES. 461 

second, the next best in strength, and so on, the last 
Table being the weakest iron. 

The test of the gun metal, Table 89, page 460, showed 
the planed bars of a very coarse grain partaking of a 
fibrous nature, somewhat after a good grade of wrought 
iron, having a fracture of a dark color. The metal 
of the rough bars showed the fracture in the one- 
half-inch square bar to be strictly white and in the 
one-inch square test bars to be of a crystalline mot¬ 
tled nature, and in the rough one and one-eighth inch 


TABLE go.'—TRANSVERSE TESTS OF CHILL ROLL IRON. 


No. Test. 

Common rule 
measure¬ 
ment. 

Mierom’t’r 

measure¬ 

ment. 

Deflec¬ 

tion. 

Broke at 
in 

pounds. 

Strength per 
square 
inch 

in pounds. 

14 

Rough bars. 

V 2 in. square. 

.509 in. 

.120 in. 

230 

888 

1,840 

15 


.518 “ 

.150 “ 

300 

1,119 

2,400 

16 

Rough bar. 

1 in. square.. 

1.032 in. 

.120 in. 

2,590 

2,432 


17 

Rough bar. 

i}4 in. diam. 

1.140 in 

.150 in. 

3,040 

2,980 


18 

Turned bar. 

in- diam. 

1.124 in. 

.190 in. 

3,020 

3,044 



Test bars furnished by Lewis Foundry & Machine Co., Pittsburg, Pa. 
Tested at the works of McConway & Torley, Pittsburg, Pa., June 27th, 1894, by 
J. B. Nau, Allegheny, Pa. Witnessed by R. G. G. Moldenke, K. M., Ph. D. 


diameter bars of a similar character, but to a little 
less degree than shown in the one-inch square bars. 
The large open-grained bars, or those of numbers 3, 
4, 5, 9, 10 and 11, illustrated in Table 89, were planed 
from the muzzle disc of a 12-inch mortar casting, and 
bars 1, 2, 6, 7, 8, 12 and 13 were cast with metal 
which was used to pour a lower base ring for a 12- 
inch spring return mortar carriage. The charge of 
iron for the mortar was very much harder than that 
used for the base ring, but as it was cast in a very 






































462 


METALLURGY OF CAST IRON. 


large mass and cooled very slowly it is not surprising 
that the fracture shows the iron in the mortar body to 
be much softer (or open-grained) than that in the test 
bars from the base ring. The tensile strength of the 
two specimens taken for acceptance of the 12-inch re¬ 
turn mortar or lower base casting as above described 
was as follows: 

No. 1 . . . 37,100 lbs. No. 2 . . . 37,000 lbs. 


TABLE 91. —TRANSVERSE TESTS OF CAR-WHEEL IRON. 


No. Test. 

Common rule 
measure¬ 
ment. 

Microm’t’r 

measure¬ 

ment. 

Deflec¬ 

tion. 

Broke at 
in 

pounds. 

Strength per 
square 
inch 

in pounds. 

19 

20 

21 

Rough bars 

]/ 2 in. square. 

»( it 

4 4 4 < 

.474 in. 
.496 “ 

• 49 1 “ 

.090 in. 
.090 “ 

.090 “ 

273 

280 

278 

1,213 2,184 
1,138 2,240 
1,18 2,224 

22 

23 

24 

Rough bars 

1 in. square. 

(4 4 4 

4 4 44 

1.012 in. 

1 022 “ 
1.007 ‘‘ 

.075 in. 
.074 “ 

•075 “ 

2.535 

2 . 4 X 5 

2,294 

2,476 . 

2,313 . 

2,262 . 

25 

26 

27 

Rough bars 

iJ4 in. diam. 

4 4 4 4 

4 4 4 4 

1 090 in. 
1.072 “ 
X.I 35 “ 

.111 in. 
.100 “ 

.100 “ 

2,340 

2,360 

2,568 

2,508 . 

2,615 . 

2,538 . 

28 

Turned bar. 

1 Ya in. diam. 

1.174 in. 

.170 in. 

3.050 

2,819 . 


Test bars furnished by A. Whitney & Sons, Philadelphia, Pa. Tested by 
tjohn R. Matlock, Jr., at the works of Riehle Bros.’ Testing MachineCo., Phila- 
jdelphia, Pa., June 27th, 1894. Witness, W. C. Cutler. 

In the chill roll iron, Table 90, page 461, a few of 
the pieces were selected after having been broken 
for transverse strength and pulled for the tensile 
strength. Bar No. 15 pulled 6,100 pounds; No. 16 
pulled 23,700 pounds; and No. 17 pulled 30,100 pounds. 
The iron in the half-inch bars showed a white crystal¬ 
line fracture, likewise the one-inch square. The one 
and one-eighth inch diameter rough bars showed a very 
close knit grain tending to a light color. The one 
and one-eighth inch turned bars are also very close 






















































STRENGTH IN SPECIALTY MIXTURES. 


463 


grained, a little darker in color than the one and one- 
eighth inch bars, but both of the latter exhibit to an 
expert the appearance of great strength as being of 
exceptionally strong metal. 

The iron in the car wheel, Table 91, page 462, shows 
the half-inch bars to be white and crystalline. In the 
one-inch square bar the iron is mottled, tending to 
white. In the one and one-eighth inch round rough 
bars the metal is more evenly mottled and less white 
than in the one-inch square. The one and one-eighth 
inch round turned bars show a very rich dark gray 
color. Bar No. 26 pulled tensile 23,270. This mix¬ 
ture proved to be an excellent iron. 

TABLE 92. —TRANSVERSE TESTS OF HEAVY MACHINERY IRON. 


No. Test. 

Common rule 
measure¬ 
ment. 

Mierotn’t’r 

measure¬ 

ment. 

Deflec¬ 

tion. 

Broke at 
in 

pounds. 

Strength per 
square 
inch 

in pounds. 

29 

30 

31 

Rough bars. 

V2 in- square. 

I < it 

<< if 

.504 in. 

•503 “ 

•504 “ 

.195 in. 

.220 “ 

.185 “ 

380 

432 

372 

1,496 3,040 
1,707 34-6 

1,465 2 976 

32 

33 

34 

Rough bars. 

1 in. square. 

ii it 

(1 if 

x 004 in. 
1.009 ‘ 
1.007 “ 

.100 in. 
.090 “ 

.1 0 “ 

2,464 

2,510 

2,640 

2,444 . 

2,465 . 

2,604 . 

35 

36 

37 

Rough bars. 

i l /z in. diam. 

I( it 

f i i i 

1.137 in. 

1 135 “ 

1 143 “ 

.100 in. 
.120 “ 

.100 “ 

2,786 

2,824 

2,500 

2,745 . 

2 , 79 i . 

2,437 . 

38 

39 

40 

Turned bars. 

in- diam .. 

>( «i 

<< it 

1.T25 in. 
1.12; “ 

1.124 “ 

.120 in. 
.150 “ 

.140 “ 

2,257 

2,488 

2,344 

2,271 . 

2,303 . 

2,363 . 


Test bars furnished by the Walker Manufacturing Company, of Cleveland, 
Ohio. Tested by Thomas D. West, at the T. D. West Foundry Co., Sept. 18th, 
1894. Witnesses, Geo. H. Boyd and G. M. Mcllvain. 


The iron in the above half-inch test bars presents a 
very close, compact grain, tending to white. The one- 
inch square bars show a close, dense fracture, tending to 
alight gray color. The one and one-eighth inch round 























































464 


METALLURGY OF CAST IRON. 


bars are less dense and present more of a dark gray color 
than the one-inch square bars. The turned bars show 
a fine, rich-colored, compact iron, such as would stand 
exceptional wear and resistance to fracture. Bar No. 
^34 pulled 26,160 pounds, and No. 35, 28,676 pounds. 
For medium to heavy machinery, this metal should 
make a most serviceable casting. 


TABLE 93. —TRANSVERSE TESTS OF LIGHT MACHINERY IRON. 


No. Test. 

Common rule 
measure¬ 
ment. 

Microm’t’r 

measure¬ 

ment. 

Deflec¬ 

tion. 

Broke at 
in 

pounds. 

Strength per 
square 
inch 

in pounds. 

4 i 

Rough bar. 

l / 2 in. square. 

•499 in. 

.200 in. 

454 

1,823 3,632 

42 

43 

44 

Rough bars. 

1 in. square. 

<1 it 

ii i i 

1.016 in. 

1.021 “ 
1.008 “ 

.130 in. 
.125 “ 

.115 “ 

1,710 

1,760 

1,800 

1,657 . 

1,688 . 

i, 77 i . 

45 

46 

47 

Rough bars. 

in- diam. 

«( it 

ii <1 

1.146 in. 
1156 “ 

1.141 “ 

.160 in. 
.180 “ 

.180 “ 

L 795 

2,220 

1,980 

i, 74 i . 

2,115 . 

L 938 . 

48 

49 

50 

Turned bars. 

il4 in. diam. 

it it 

ii ii 

1.162 in. 

1 160 “ 

1175 “ 

.200 in. 
.210 “ 

.210 “ 

L 705 

1,720 

L 775 

1,609 . 

1,628 . 

1,637 . 


Test bars furnished by Taylor, Wilson & Co , Ltd., Allegheny, Pa. Tested 
by J. B. Nau, at the works of McConway & Torley, June 19th, 1894. Witness, 
R. G. G. Moldenke, E. M., Ph. D. 


* The fracture of above set of tests shows an excep¬ 
tionally good iron for light work. The tests record 
above the average for soft iron as regards strength. 
The color is a rich gray, devoid of that silver look 
many castings display that are desired to be of a soft 
quality. The half-inch bars are the closest grained, 
the one-inch square the next in order, then comes the 
one and one-eighth inch in the rough, followed by the 
turned one and one-eighth inch bars, which are the 
most open-grained, rich in color and graphite. A 
few of these bars were pulled for the tensile strength. 























































strength in specialty mixtures. 465 

No. 41 stood 6,000 pounds; No. 43 stood a pull of 
19,000 pounds, and No. 47 separated at 21,120 pounds. 


TABLE 04.— TRANSVERSE TESTS OF STOVE PLATE IRON. 


No. Test. 

Common rule 
measure¬ 
ment. 

Microm’t’r 

measure¬ 

ment. 

Deflec¬ 

tion. 

Broke at 
in 

pounds. 

Strength per 
square 
inch 

in pounds. 

5 T 

52 

53 

Rough bars. 

in. square. 

U (C 

(( (( 

•475 in. 
.476 “ 

•474 “ 

.220 in. 
.260 “ 

.250 “ 

160 

170 

150 

711 1,280 

747 1,360 

669 1,200 

54 

55 

Rough bars. 

1 in. square. 

«« t ( 

•994 in. 
•975 “ 

.150 in. 
.100 “ 

I >757 

1,660 

L 778 . 

L 747 . 

56 

57 

Rough bars. 

1% in. diam. 

M II 

1.118 in. 
1.126 “ 

.170 in. 

. 170 “ 

1,780 

L 775 

1,813 . 

1,783 . 

58 

59 

60 

Turned bars. 

i}4 in. diam. 

1C (( 

H Cl 

1.127 in. 

1.140 “ 
1.125 “ 

.180 in. 
.183 “ 

.180 “ 

1,320 

1,440 

L 335 

1,322 . 

1,412 . 

L 343 . 


Test bars furnished by Bissell & Co., Allegheny, Pa. Tested by J. B. Nau, 
at the works of McConway & Torley, June 20th, 1894. Witness, R. G. G. 
Meldenke, E. M., Ph. D. 


The above tests of the inch square and round bars 
assert this iron to be of good strength for the work 
intended. A factor in this series which will no doubt 
attract attention is the light load the half-inch bar 
stood in comparison with the larger sizes and only 
goes to further demonstrate the erratic and deceptive 
results which we may expect with small test bars. No. 
53 stood 6,000 pounds tensile; No. 54 stood 16,600 
pounds; and No. 60 stood 17,150 pounds. 

In studying Table 95, one is impressed with the 
uniformity of the load the bars stood and also the 
weight necessary to break them, for as a general thing 
“ white iron ” exhibits little strength in castings. The 
tests would lead us to decide that the greatest weak¬ 
ening element in castings made of 4 ‘ white iron ” is 
due to excessive contraction, which is characteristic of 


















































METALLURGY OE CAST IRON. 


A 66 


TABLE 95. —TRANSVERSE TESTS OF SASH WEIGHT OR WHITE IRON. 


No. Test. 

Common rule 
measure¬ 
ment. 

Microm’t’r 

measure¬ 

ment. 

Deflec¬ 

tion. 

Broke at 
in 

pounds. 

Strength per 
square 
inch 

in pounds. 

61 

Rough bars. 

V 2 in. square. 

(< t< 

.488 in. 

.062 in. 

175 

735 

1,400 

62 

.484 “ 

.060 “ 

160 

683 

1,280 

63 

«( << 

.487 “ 

.062 “ 

170 

717 

1 360 

64 

65 

66 

Rough bars. 

1 in. square. 

(I M 

(1 «< 

.992 in. 

• 9-4 “ 

.992 “ 

.o'o in. 
.040 “ 

•055 “ 

1.340 

L 325 

1.365 

1,361 

L 34 i 

1,386 


67 

Rough bars. 

in. diam. 

1.114 in. 

.050 in. 

L 355 

L 392 


68 

69 

it ii 

1.113 “ 

1.117 “ 

•055 “ 

.050 “ 

1,440 

1,320 

1,480 

L 346 



Test bars furnished by E. E. Brown & Co., Philadelphia, Pa. Tested by W. 
C. Cutler, at the works of Riehle Bros.’ Testing Machine Co., Philadelphia, 
Pa., June 29th, 1894. 


“ white iron. ” Many castings made of white iron have 
been known to fly to pieces from internal contraction 
strains when cooling, without a jar or the least weight 
being placed upon them. The reason for not show¬ 
ing any turned bars in this test is due to the diffi¬ 
culty or rather the impracticability of machining such 
a hard metal. Bar No. 69 pulled 7,125 pounds. The 
fracture of all the bars is of a very pronounced crys¬ 
talline white appearance, as can be seen in Fig. 101 
on page 473- 


table 96.— SUMMARY OF THE STRONGEST TESTS. 


No. 

of 

bar. 

Transverse 
Strength per 
square inch. 

No. 

of 

bar. 

Tensile 
Strength per 
square inch. 

•Specialties 
of mixtures. 

12 

3,686 


-37,100 

Gun Metal. 

17 

2,980 

17 

30,100 

Chill roll. 

26 

2,615 

26 

23,270 

Car wheel. 

36 

2,791 

35 

28,676 

Heavy machinery. 

46 

2,115 

47 

21,120 

Light machinery. 

56 

1,813 

60 

17,150 

Stove plate. 

68 

1,480 

69 

7,125 

Sash weight. 


-This tensile test is No. i of Mr. R. A. Robertson’s gun metal reoort. 



























































Strength in specialty mixtures. 


467 


Having; completed the record of tests, it is now in 

order to learn what they prove. It will require but 
little study of the Tables to find that the small bars do 
not record any true variation in degrees of strength, 
no matter what quality of iron is used. They assert 
that gun metal, chill roll, car wheel and heavy ma¬ 
chinery are no stronger than light machinery or soft 
grades of irons. Any one experienced in the handling 
or use of cast iron knows that the first four grades of 
iron are stronger and have a higher commercial value 
for strength than the fifth one. 

To further illustrate the impracticability of using 
bars below one square inch area, we show an average 
of the strength of the one-half inch square and one 
and one-eighth inch round rough bars of all such tests 
given in this Chapter in the following Table 97 : 


TABLE 97 '—STRONG IRONS. 

Average of x / 2 in 
square bars. 


Average of ipsin. 
round bars. 

398 pounds. 

265 

277 

395 

...Gun metal. 

3,686 pounds. 
2,980 “ 

2,553 

2,657 “ 

.Chill roll. 



WEAK IRONS. 


Average of y 2 in. 
square bars. 


Average of i%in. 
round bars. 

454 pounds. 

160 

167 

.Stove plate. 

I- 93 1 pounds. 
1 , 79 ? “ 

1,406 



It cannot but be plain from the averages in Table 97 
that the half-inch square bar is a size readily af¬ 
fected by the least change in the dampness of sands or 


































468 METALLURGY OF CAST IRON. 

fluidity of metal, to afford any fair knowledge of the 
true relative differences in strength of cast iron. 
The half-inch bars from gun metal and the half¬ 
inch bars from heavy machinery practically show 
each to be of the same strength, where the one and 
one-eighth round bars indicate what we would nat¬ 
urally expect, namely, that the gun metal is materi¬ 
ally stronger than the heavy machinery iron. Then 
again, the half-inch bars would indicate that the heavy 
machinery iron was very much stronger than the roll 
irons. The strength of the half-inch bars for light 
machinery, 454 pounds, indicates such iron to be 
stronger than gun metal, chill roll, car wheel or heavy 
machinery iron, while the one and one-eighth inch 
round bars show the light machinery to be but 1,931 
pounds, as compared with 3,686 pounds for gun metal, 
2,980 pounds for chill roll, 2,553 pounds for car wheel 
and 2,657 pounds for heavy machinery. The half-inch 
bars show a breaking load of 160 pounds for stove 
plate and 167 pounds for sash weight or “ white iron,” 
indicating that the latter is the stronger iron, while 
our one and one-eighth inch round bars show a 
strength of 1,798 pounds for stove plate, and only 1,406 
pounds for sash weight iron, thus thoroughly demon¬ 
strating that one inch square area bars will fairly record 
the true relative degrees of strength of cast iron, 
whereas the half-inch square bar gives us absolutely 
little knowledge or indication of any difference in 
strength between one mixture and another, or any 
irons used in the different specialties of iron founding. 
A fact that further demonstrates the impracticability 
of using small.test bars is that the tensile strength of the 
Table 96 records a uniformity in degrees of strength 


STRENGTH IN SPECIALTY MIXTURES. 469 

closely corresponding with the transverse load of one 
square inch area bars in the same Table, and which 
would have been still better could the bars only have 
been cast on end. 

The next size and form of bar to consider is that 
of the one-inch square. In comparing the fracture of 
the square with those of the round bars (see pages 472 
and 473), the grain of the former will average denser 
and all square bars, excepting those of “ white iron ” 
fracture, show the bars to be much denser at the cor¬ 
ners than on the flat surface section of the bars, thereby 
giving a less uniform grain and causing more in¬ 
ternal strains in a square bar. They are also weaker 
than a round bar. This point the records of Table 
98 fully prove, by showing that the round bars record 
a greater strength than square bars of like areas. I 
do not wish to be understood as saying we should 
adopt the method which will show the greatest 
strength in the bar, but rather the one best to insure 
knowledge of the natural relative qualties of cast 
iron mixtures, and this the round bar will do. 

TABLE 98. —SUMMARY OF BEST STRENGTH AVERAGES OF ROUGH 

ROUND VS. SQUARE TEST BARS. 


Gun metal. 

it it 

Chill roll . 

H U 

Car wheel. 

it it 

Heavy machinery 

(I !< 

Light machinery. 

u a 

Stove plate . 

a a 

Sash weight. 

(t << 


Average of ij 4 in. round bars.3,686 lbs. 

“ “ 1 in. square bars.3,344 “ 

“ “ 1% in. round bars.2,980“ 

“ “ 1 in. square bars.2,432“ 

“ “ 1% in. round bars.2,553“ 

“ “ 1 in. square bars.2,350 “ 

, “ “ 1% in. round bars.2,657“ 

“ 1 in square bars.2,504 “ 

“ ' “ 1% in. round bars.1,931 “ 

“ “ r in. square bars.1,705 “ 

“ 1% in. round bars.1,798“ 

, “ “ 1 in. square bars.1,763“ 

, “ “ 1 % in. round bars... 1,406 “ 

“ “ 1 in. square bars. .1,362“ 




































470 


METALLURGY OF CAST IRON. 


This Chapter presents facts which should greatly aid 
in settling all disputes as to the value of the round over 
the square bar for recording the best natural strength 
of cast iron, and that we should not use a bar less 
than of one square inch area.* The tests exhibited are 
all of sound fracture, and in all bars but those for 
sash weight iron could be machined as described on 
page 300. For tests of larger round bars than one and 
one-eighth inch diameter, and a discussion on the 
utility of test bars, see pages 533, 536, 577 and 579. 

Previous to this series of tests, etc., being first pub¬ 
lished, the author had no knowledge of any person 
thinking to advance information on the physical prop¬ 
erties of cast iron, working other than in one “grade,” 
and drawing conclusions from this as being applicable 
to anything that might come under the head of cast 
iron, which is a broad term and means any “grade” 
that the metalloids, silicon, sulphur, phosphorus and 
manganese when combined with metallic or “ pure 
iron, ’ ’ make workable for conversion into castings. 
While it is true the quality of “ grades ” being in cast 
iron was not recognized as it should be by experi¬ 
menters, etc., making or reporting physical tests, the 
author is pleased to note that this work has caused 
cognizance being taken of this, as such a course places 
all in a position to arrive at correct conclusions to the 
sooner fathom any phenomena that may puzzle or 
make mysterious the workings of cast iron. It would 
be well to study Chapter XX. in connection with this 
paragraph. 

A study of the cuts seen in Figs. 95 and 102 will 

show how the metal is best permitted to have its 

* The American Foundrymen’s Association adopted resolutions that test 
bars smaller than I*4-inch diameter were not recognized, see pages 573, 577 



STRENGTH IN SPECIALTY MIXTURES. 


471 


carbon evolve uniformly in the graphitic form, by 
the use of the round test bar, hence, again showing 
this to be the best form which we could adopt for 
obtaining knowledge of the relative strength, etc., 
of cast iron. It will be seen that by a use of the one- 
half square bar with weak irons, the carbons remain 
mostly in the combined state, and when used for 
strong iron, its body becomes “white” or crystalline. 
In the one-inch square bars the corners, as may be 
seen, are much deeper in combined carbon or dense 
in grain than on the flat surface, as seen at A B, Figs. 
97 and 98, and instead of its skin or shell being an 
even thickness or of a uniform texture, as seen in the 
round bars at D and E, Figs. 97 and 98, it is very ir¬ 
regular. Furthermore, although the square bars are 
of about the same area as the round bars, still we find 
the latter has the greatest body of metal in the gra¬ 
phitic form. 

Complete analyses of all the specialties here exhib¬ 
ited in combination with others are presented in Chapter 
XLIV. These will assist in defining the percentage of 
chemical properties best to exist in an iron or mixtures 
to secure the various physical conditions and qualities 
desired in castings at the present day. Nos. 29 and 30, 
Fig. 102, illustrate the affinity of iron for sulphur, being 
the bars described in Chapter XXX., in which sulphur 
or brimstone was placed in the ladle after No. 30 had 
been poured. The white ring at H, No. 29, shows the 
hardening effect of sulphur. 




No. i. 


No. 2. 


FIG. 95.—GUN METAL. 


SILICON 1 . 19 | SULPHUR .055. 



No. 


No. 


No. 5. 



No. 6. 



FIG. 96. —CHILL ROLL. SILICON. 77; SULPHUR .058. 


No. 8. 


No. 9. 


No. 7. 


FIG. 97. —CAR WHEEL IRON. SILICON .66; SULPHUR .127. 



FIG. g 8 . —HEAVY MACHINERY IRON. SILICON I.50; SULPHUR .IIO. 




No. 15. 


A 


B 


No. 14. 


No. 16. 


No. 17. 














FIG. 99. —LIGHT MACHINERY. SILICON 1.83; SULPHUR .078, 



No. 18. 


No. 19. 

FIG IOO.— STOVE PLATE IRON. 


No. 20. 

SILICON 2.59 


No. 21. 

SULPHUR .072. 



No. 22. 

FIG. IOI. —SASH WEIGHT IRON. SILICON. 180 ; SULPHUR. 138 . 



No. 25. 


No. 23. 


No. 24. 



No. 26. 



No. 27. 

FIG. 102.—SULPHUR TEST. 


No. 28. 











CHAPTER LXI. 


COMPUTATION OF RELATIVE STRENGTH 

OF TEST BARS. 

The rule for computing the relative strength of test 
bars (see page 476) is to divide the breaking load by 
the area of the bar, at its point of fracture. It is to 
be understood that this rule can be applied only to bars 
of the same length and cross section, or made from 
the same pattern, in sizes or areas to equal i}£ inch to 
2% inches diameter or such bars as shown on pages 
536 and 573, for the purpose of making - compari- 
' sons of any difference that may exist in the area of 
test bars made from off the same pattern, due to a 
straining, etc., of the mould in which the bars were 
cast. While the compilation derived by the rules in 
Table 99, page 476, are placed under the head 
of “ Strength per square inch ” in most of the Tables 
of tests in this work, such is given as a matter 
of form, or for relative comparisons, and not as 
absolute strength per square inch. The author 
has presented the rule given in Table 99 for the 
reason that it is the simplest for ordinary shop 
testing, and takes better cognizance of the prac¬ 
tical elements for everyday use in a standard bar 
than any other formula of which he has knowledge. 
Whatever systems are advanced for making relative 
comparisons in the transverse or tensile strength of 
iron, no matter what size of a bar we use, be it of one 
inch, two inches, or three inches area, square or round, 
the author claims that none should be recognized as 


RELATIVE STRENGTH OF TEST BARS. 


475 


worthy of any serious consideration as a standard that 
requires us to take into account more than one-eighth 
inch from the size of the test bar pattern used. The 
moment we attempt to figure up or down, to determine 
a metal’s strength per square inch, or the more we are 
diverted from the exact size of the bar actually tested, 
the more we will err in drawing correct comparative 
deductions in any “ grade ” of iron. In order to 
obtain a relative knowledge of the strength of an iron 
we must confine tests to the use of one size of a bar 
(see page 534), let that be a one-inch, two-inch, or three- 
inch square area bar, and its computation should only be 
permitted in taking into account any variations which 
may exist due to irregular work in the moulding and 
casting of any one of the three sizes that may be used. 

In testing bars, this effect from irregularity in 
moulding which can cause a variation in the size of 
test bars, made off from the same pattern, should be 
taken note of in compiling any records of strength 
filed for reference or comparison. Note should be 
taken of the least variation which might exist in 
the size of a standard test bar, as a few thousandths 
part of an inch in the diameter of a bar is multi¬ 
plied about three times in its circumference. A 
little variation in the size of a test bar can make a 
bar considerably stronger or weaker, according as its 
diameter is decreased or increased from the size of the 
pattern from which the test bars are moulded. In com¬ 
piling this work, it will be observed that the author 
has thought it correct to recognize this factor, and hence 
the adoption of the column, “ Strength per square 
inch,” seen with some of the tables given herewith. 
In order that the reader may understand how any 


47 6 


METALLURGY OF CAST IRON. 


difference in the relative strength of test bars 
was obtained for the tables, we give two examples 
seen on this page, as one method is necessary 
for a square bar and another for a round bar: The 
author could never perceive wherein the formulae 
used for figuring the strength per square inch, as 
advanced by our text books, etc., had any bearing on 
the actual area of a test bar and the load at which it 
broke; in fact, if in 1901 a founder should send the 
area and tests of round and square test bars to recog¬ 
nized authorities on mathematics to have their strength 
per square inch computed, the chances are they would 
present such figures that he would be liable to wonder 
if present formulae for cast iron were not invented 
rather for the purpose of distorting facts or making 
figures lie than for furnishing true data. The author 
has referred to this subject on several occasions since he 
published the methods for computation shown in table 


TABLE 99. —SQUARE BAR. TEST NO. 6. PAGE 460. 


Micrometer 
Meas. 
1.002 in. x 


Square. 
1.002 in. 


Breaking load. 
3,500 lbs. 


Area of bar. 

1.004 square inches. 

Area. 

1.004 — 3,486 lbs. strength per sq. in. 


ROUND BAR. TEST NO. 12. PAGE 460. 
Diameter. Diameter. Square of diameter. 

1.132 in. x 1.132 in. = 1.281424 square inches. 

Square of diam. Decimal. Area. 

1.281424 x .7854 *= 1.006 square inches. 

Breaking load. Area. 

3,708 - 4 - 1.006 = 3,686 lbs. strength per sq. in. 


99, and was pleased to note that at the meeting of 
the American Society of Mechanical Engineers, St. 
Louis, May, 1896, Prof. C. H. Benjamin came out 
openly in a letter discussing the testing of cast iron 
and attacked the usual formulae for loaded beams as 


RELATIVE STRENGTH OF TEST BARS. 


477 


being incorrect, insisting that a reform should be 
enacted in this field of mathematics. In his letter he 
expressed the opinion, as stated by the American 
Machinist , that the terms “modulus of elasticity,” 
“elastic limit,” etc., were entirely out of place as 
applied to cast iron, and should not be used at all in 
connection with that material, and that the usually 
accepted formulae for strength of beams would not hold 
good for cast iron beams, as had been shown by tests 
made by himself for the committee. 

The author trusts that the good work started at St. 
Louis will result, before many years, in our having 
some standard for computing the strength of cast iron 
that can be recognized as more practical or more cor¬ 
rect than our present formulas for figuring different 
lengths and sizes of bars or loaded beams. It is as 
essential to have correctness in formulas for figuring 
the strength of cast iron as it is to have correct systems 
for casting and testing such grades of metal. (See 
page 530.) 

To any desiring to use larger bars than the one 
and one-eighth inch diameter shown in Table 99, and 
wishing to keep even figures as with a two-inch or 
three-inch area section, as some may desire to do, the 
only difference would be to have the figures 1.596 or 
1.955, as the case may be, replace the 1.128, which is 
the diameter of a bar equal to the area of a one-inch 
square bar. It may be well to mention at this point 
that the Riehle Bros, of Philadelphia and others now 
use the method for computing the strength of test bars 
shown in Table 99, page 476. 


CHAPTER EXIT 


VALUE OF MICROMETER MEASURE¬ 
MENTS IN TESTING. 

“ What is worth doing at all, is worth doing well,” 

is an old maxim, and never more applicable than to the 
subject of testing. It can be readily observed that 
the author is an advocate of utilizing every factor 
that can, in any manner, assist in lessening erratic 
records and advance testing of cast iron to its high¬ 
est perfection. Such advocacy would be inadequate 
did the author not argue for the adoption of the mi¬ 
crometer to measure the area of test bars at the point 
of fracture. The micrometer would be used much 
more than it is at the present time, did testers only 
more fully realize the difference a few thousandths of 
an inch in the diameter of a bar can make in the 
strength records, especially when the same are re¬ 
duced to make relative comparison of strengths. 

Many would be surprised to learn how often they 
have been deceived in according differences in strength 
to records obtained simply by calipers and common rule 
in considering the size of bars for comparisons. If the 
micrometer had been used and the area reduced to 
make relative comparisons as illustrated on page 
475, testers would ofttimes have found bars, which 
were conceded by the breaking load records to be the 
Wrongest, to prove the weakest test of iron. 


VALUE OF MICROMETER MEASUREMENTS. 


479 


It is impossible to obtain rough bars of the same 
area. There is sure to be some difference in their 
sizes. It is not unusual to find one-inch area, etc., 
bars to be from one-sixteenth to one-eighth larger in 
diameter or the square than the pattern used and to 
find that testers make no note of such difference, but 
are wholly guided by the weight at which the bat 
broke. If one was one hundred or two hundred more 
than others, the highest was accepted as the strongest 
and best test, regardless of the bar’s exact area. 

To illustrate how a small bar breaking with a heavier 
load than the large bar (each differing but a few thou¬ 
sandths of an inch in their area), may often, if not re¬ 
duced to relative strengths, etc., deceive a tester 
200 to 400 pounds in accepting common rule measure¬ 
ment and the actual load in thinking he has a true 
record of the iron’s strength, the reader is referred 
to Table 89, tests Nos. 6 and 8, on page 460, showing 
transverse tests of gun metal. There we find two 
bars which, if the actual breaking loads were accepted, 
would deceive the tester 269 pounds, or in other words, 
instead of his believing he had one bar only 72 pounds 
stronger than the other, he actually had a difference of 
269 pounds, as stated above. This should aid to clearly 
illustrate the importance of micrometer measure¬ 
ments, wherever the tester desires to truly ascertain 
whether any difference actually exists in the strength 
of his mixtures or the character of the iron produced. 

Another feature well to be noticed is that of the 
impractibility of obtaining bars exactly round or 
square, or exact duplicates of their pattern. Many 
testers take but one measurement of a bar, while others 
take no measurement at all. Any following either 


480 


METALLURGY OF CAST IRON. 


practice might almost as well omit their testing, for 
they are as liable to be misled as be correct in their 
conclusions. In obtaining the area of a round or 
square bar two measurements, at least, should be 
taken, added together, and then divided by two to 
obtain the average of their sizes to assure a tester that 
he has knowledge of what is closely the true total area 
of bars. Those desirous of closely following mixtures, 
etc., by physical tests to obtain true knowledge of the 
strength of their product, can not ignore the value 
of micrometer measurements. For scientific research, 
at least, such methods must be strictly followed. To 
find decimal equivalents for use in micrometer measure¬ 
ments, see Table 139, page 594. 


CHAPTER LXIII. 


OPERATING TESTING MACHINES. 

Obtaining true results or close records in testing is 
often assisted as much by careful work and system in 
operating testing machines as by correct methods in 
the moulding, casting, etc., of test bars. 

In obtaining the transverse strength and deflection 
of bars cast flat they should always be laid on the bear¬ 
ing blocks the same way. The importance of this is 
realized when we consider that the down or “ nowel ” 
side of a one-inch area round or square bar can be 
made to show a strength of 300 to 400 pounds more 
by having the ‘ ‘ nowel ’ ’ side resting on the blocks 
than where the cope side is so placed, a quality clearly 
proven in Chapter LXV., page 488. 

If bars are cast on end, it is well to have the down or 
upper cast end always pointed the same direction.* To 
insure this in the methods advocated by this work, a 
small, flat depression is cast in the bars, so as to permit 
their always finding a good bearing at the same spot 
of the bars, as seen at X, Fig. 103, next page. 

The same speed in testing should always be main¬ 
tained as far as possible, as whether a bar is broken 
fast or slowly can make a difference in results. A 
comfortable speed, which can be always readily main¬ 
tained, should be adopted. In obtaining tensile 

* This is essential, as it assists in obtaining an approximate 
area at the breaking point, as the taper of the patterns and strain¬ 
ing of the mould from head pressure are liable to make the area 
of the bars vary at different heights. 



482 


METALLURGY OR CAST IRON. 


strength of test bars, every care should be taken to 
prevent one side being strained or pulled more than 
the other. The grip should be such as to cause an even 
pull all over the area of the specimen, in order to ob¬ 
tain the true tensile strength of the iron. See page 450. 

Another essential in operating testing machines is 
that of applying the 
weight as steadily as 
practicable. At Fig. 

104 is shown the up¬ 
per section of a type^ 
of testing machine 
now being largely used, in which the oscillation of 
the beam F, from the lower stop H up to the up¬ 
per stop K, in some cases may mean a load of 100 
pounds, which if brought up or down quickly re¬ 
sults in a strain like an impact blow. A good plan to 
follow in using a machine of this design is to place 
one hand around the stop at K. By this plan, less 
room is allowed for the oscillation of the weighting 




beam and the hand readily informs the mind of any 
upper movement, so that the sliding poise can be 
made to balance the beam before a bar could break 
to make it questionable within one hundred pounds of 
just what is its true strength, by reason of the beam 
F rising suddenly to the stop K. 







































































CHAPTER LXIV. 


ROUND vs. SQUARE TEST BARS.* 

The square test bar, cast flat, was, prior to 1890, 
almost solely employed. The author first advocated 
the use of a round test bar in an article in the Ameri¬ 
can Machinist , June 6, 1889. He is aware that the 
square bar, cast flat, has been the basis of elaborate 
tables of transverse strength for use by engineers, etc., 
and for publication in our scientific text-books; yet, in 
spite of all this, the practice is wrong. 

Metal, in cooling, arranges its crystals in lines per¬ 
pendicular to the bounding planes of the mass, or, in 
other words, the crystals arrange themselves along the 
lines the waves of heat travel in passing outward from 
the casting as it cools off. To assist in illustrating this 
subject I have taken the following description and cuts 
(Figs. 105 and 106) from Spretson’s work on founding. 
Speaking of the cuts, Mr. Spretson says: 

In the round bar the crystals are all radiating from the center. 
In the square bar they are arranged perpendicular to the four 
sides, and hence have four lines, in the diagonals of the square, 
in which terminal planes of the crystals abut or interlock, and 
about which the crystallization is always confused and irregular. 

This is said to be very plainly exhibited by the effect 

* A revised extract of a paper read before the Western Foundry- 
men’s Association, June, 1S94. 



4*4 


METALLURGY OF CAST IRON. 


of manganese in steel castings showing a contrast be¬ 
tween round and square fractures. 

A study of Figs. 105 and 106 impresses one with the 
importance of arranging for the greatest possible uni¬ 
formity in providing for the radiation of heat from a 
test specimen, and also to afford it the most favorable 
condition to arrange its crystals uniformly through¬ 
out its body. It requires no great stretch of the imag¬ 
ination to conceive what a great influence the simple 
matter of slight differences in the “ temper ” of sand 
in a mould may 
have in causing 
non-uniformity in 
the even texture 
of a square bar 
compared to the 
even structure 
possible in a round 
bar. Mr. John E. 

Fry, in a paper before the Eastern Association, May 2, 
1894, condemning one-half inch square test bars, clearly 
.illustrates the effect of a little variation in the “ tem¬ 
per ” or dampness of sand, often making small bars 
wholly unreliable as a test for the relative strength 
of any kind of cast iron. 

Before leaving Figs. 105 and 106, let me call attention 
to their clear exemplification of the necessity of cast¬ 
ing test bars on end, in order to insure uniform cool¬ 
ing off. The lieavy-work founder knows that metal 
first solidifies at the bottom of a mould, and if he is 
‘‘feeding” a heavy casting, the metal, by solidifying 
at the bottom first, will gradually force his “ feeding 
rod” upward, thus demonstrating that the greatest 



fig . 105. 


fig. 106. 










ROUND VS. SQUARE TEST BARS. 


485 


line for radiation or line for heat to escape is upward, 
or through the “ cope of a mould. For this reason, 
if we would break a casting a foot square into halves 
down the center of its vertical position, as when cast, 
we would find the last spot to solidify would gener¬ 
ally be about three inches from the top, or one-fourth its 
height below the cope surface. It makes no difference 
how small a body of metal may be, the same principle 
is applicable to it as to the large body, and goes to 
fully demonstrate the irregularity for a central point 
of latest solidification which must exist in a test bar 
cast flat. Then again, uneven cooling is bound to 
cause more or less internal contraction strain in a test 
bar. It must be evident that a test bar cast on end 
will have an even radiation from all portions of its 
surface at any height, and thus give to the bar the 
best uniform grain throughout any section and also 
the best opportunity to lessen strains so far as cooling 
off has any effect. More information on the necessity 
of casting test bars on end will be found in the next 
Chapter, page 488. 

The nature of all cast iron is such that any elements 
in a mould possessing heat-conducting powers, that 
will either chill or make closer the grain of the metal 
in the skin or surface, are very effective in changing 
results in the strength and contraction of iron, espe¬ 
cially in light castings or small test bars. There is a 
great difference in iron in its susceptibility to elements 
tending to chill. Some iron, if poured into a dry sand 
mould, would show a gray fracture, but if poured into an 
iron or green sand mould, would show at the surface a 
white or chilled iron, the depth of which depends upon 
the character of the iron, the thickness of castings, 


4<S6 


METALLURGY OF CAST IRON. 


etc. In Fig - . 107, we see an irregular circle, outside of 
which we find the deepest close-grained sections at 
the corners A B. The lower the “ grade ” of the 
iron and the damper the sand the deeper will these 
corners chill or close up the grain of an iron. There is 
a limit to the extent to which combined carbon shown 
in the closing of the outer grain can cause strength 
in the test bar, where it is combined with a soft center 
or graphitic core as seen at D. A test bar can, by a 
radical difference in the grain of the core and outer 
body, embody 
such contraction 
strains within its 
own elements as to 
break with a light¬ 
er load compared 
with the true natu¬ 
ral qualities of 
metal as exhibited 
by actual working results in castings or from a turned 
test bar. Degrees in “temper” or dampness of the 
sand comprising a mould have every influence in 
changing results in the corners of a test bar. A 
square bar is an erratic bar at its best; one cannot say 
what it will do in often showing different grades of 
iron to be partly the opposite of what a use of the 
castings would demonstrate. This is especially true 
where square test bars are cast flat. 

We will now turn our attention to the round bar, 
Fig. 108. It surely requires but little observation to 
impress one with the regularity of its outline compris¬ 
ing the surface or close-grained metal; and it appears 
like adding insult to injury to discuss the favorable 



fig. 107. 


fig. 108. 


ROUND VS. SQUARE TEST BARS. 


487 


conditions it presents over a square bar in permitting 
iron to show a uniform grain in a test specimen. No 
one need accept the illustration of this question as ex¬ 
hibited by the cuts (Figs. 107 and 108), as any founder 
can cast square and round test bars to ascertain the dif¬ 
ference in the grain of two such fractures for himself. 

For testing iron, by means of rough cast bars, I am 
at a loss to conceive how any one with the facts before 
him, as herein set forth, can scientifically support or 
argue for the adoption of a square test bar. When we 
consider the uniformity of radiation, crust, and grain, 
that a round bar cast on end makes practicable, and 
then look at a square bar cast flat, it does seem that we 
do not need any science but that a little use of fair 
reasoning is all-sufficient to guide us aright in deciding 
which of the two forms is the more liable to most 
closely approximate comparisons of the strength or 
contraction of iron mixtures, etc. 

The Author’s continued advocacy of the round bar, 
cast on end, since 1889 has been rewarded by the 
American Foundrymen’s Association, at its annual 
convention in 1901, unanimously passing resolutions 
recommending the round bar cast on end as the most * 
suitable for testing cast iron. This resolution also 
recommends that bars should not be smaller than one 
and one-half inches diameter. The sooner all come to 
recognize the advisability of adopting the above recom¬ 
mendations, though many may desire to use as small 
as 1 }£-inch diameter bars, which may often be permis¬ 
sible with soft grades, .the better for all interested in 
or making use of test records. An account of the A. 

F. A.’s work in bringing about the above recom¬ 
mendations is found in Chapter LXX., pages 574 to 584. 


CHAPTER LXV. 


DISCOVERY OF EVILS IN CASTING TEST 

BARS FLAT. 

At the meeting of the American Society of Mechan¬ 
ical Engineers held in New York City the week of 
December 3, 1894, the author, in a discussion on test¬ 
ing, briefly called attention to the series of tests seen 
on page 493. Before asking the reader to review the 
tests, the author wishes to comment on principles 
involved and what they demonstrate to us. in emphat¬ 
ically proving that certain practices some follow are 
not correct. It is well known that the past practice 
in moulding test bars has been upon the principle of 
casting them flat, and also that the form generally 
used has been square or rectangular in preference to 
the round form cast on end which, the author is pleased 
to note, has attracted much attention and is now (1901) 
adopted by many as the only correct method to test 
the physical properties of cast iron. The author will 
now advance more proofs to show that the round 
test bar cast on end is the best method which we 
can adopt to reduce erratic results in testing to the 
minimum. 

Early in 1894, the author discovered that in testing 
a bar cast flat for its transverse strength, by applying 
the load on the upper cast surface a much greater 


EVILS OF CASTING TEST BARS FLAT. 


489 


strength could be obtained than if the bar was turned 
the reverse side up. I have found in experimenting 
with a large number of bars one-half inch square, one 
inch square, and one and one-eighth inches diameter, 
with supports twelve inches apart, that I obtained on 
an average 30 pounds more strength for a one-half inch 
square bar, 100 pounds in the one-inch bar, and 150 
pounds in the one and one-eighth inch round bar. I 
wish these figures to be accepted only as an average of 
many tests of bars of the respective sizes given, and 
with which, as a rule, the results-have been very erratic. 

I have found in a one-half-inch square bar as much 
as 50 pounds difference in testing the two sides and in 
the one-inch square and one and one-eighth inch round 
I have found a few bars which showed from 300 to 400 
pounds difference, thereby presenting proof that cast¬ 
ing flat any form of size of bar admits of errors and 
jugglery and is wholly wrong. 

I would state that in experimenting with testing on 
the lower and upper sides of test bars, they should 
always be moulded in the same flask, poured from the 
same ladle and from the same gate. To prove my 
position on this question, I would first call attention to 
conditions which can be found by any who are suffi¬ 
ciently interested to experiment in this line. In Fig. 
109, next page, is shown a side elevation of a bar resting 
on pointed supports A B, 12 inches apart, the distance 
which the author used in his experiments. The point 
of load is shown at D. The position of the bar is the 
same as when cast or lying in its mould. In examin¬ 
ing such a bar it will be found that the metal at the 
lower side or shell E E is generally denser, or of a 
closer grain, than that composing the upper half of the 


METALLURGY OF CAST IRON. 


49° 

bar. This is caused by the lower half being cooled 
more quickly than the upper half. This gives in the 
lower half of the bar, in a sense, more combined than 
graphite carbon, which results with iron not “ white ” 
in causing the “ lower ” half to be of greater strength 
than the upper half. But the degree to which this is 
affected in flat-poured bars is largely controlled by the 
difference in the “temper” of the sand, hardness of 
ramming, degree of fluidity, speed of pouring, and 
the quality of iron used. Since these conditions can • 



not be always the same, results in testing flat cast bars 
are erratic. That one side of a flat cast bar will always 
be in line of giving more strength than another, is 
understood when we take into consideration, with 
the above, the fact that in testing for transverse 
strength, we subject the under side of the bar to an 
extension or tensile strain, and the upper side to one 
of compression or crushing. If we have the densest 
or highest combined carbon side of a bar to resist 
the extension or tensile strain, it is reasonable to 









EVILS IN CASTING TEST BARS FLAT. 


49 1 


expect it to stand a greater load than if we placed 
the most open-grained or weakest side to the ex¬ 
tension or tensile pull. Another point which proves 
that there is a difference in the cross sections of the 
grain of iron in a test bar poured flat is that if we drill 
into the end of such bars there will be found, as a gen¬ 
eral thing, a tendency for the drill to work itself more 
to the top or weak side of the test bar, as more clearly 
illustrated in Fig. no. I cannot conceive why the 
adoption of the round bar cast on end should not 
greatly lessen the causes for the past erratic results in 
testing, as my experience with these bars so cast 

makes it manifest how closely two 
bars of like area, which have been 
properly cast on end, in the same 
flask, with the same gate and out 
of the same ladle, will come to 
each other. Table 103, page 493, is 
an example of how closely round 
bars cast on end can record like 
strength. I would call attention to 
the test of twelve bars, comprising four one-half inch 
square, four one inch square and four one and one- 
eighth inch diameter, which were all moulded in one 
flask, poured with the same ladle from the same gate and 
cast flat, as seen, page 493, and then compare the four one 
and one-eighth inch round bars, which are moulded two 
in a flask, upon the principle which the author advances 
for casting test bars on end. These were cast out of the 
same ladle after the above twelve bars were poured 
flat. The ladle for pouring the above sixteen bars held 
about 150 pounds of metal. It will be seen by the 
examination of Tables 100, 101, and 102 that all the 



fig. no. 



49 2 


METALLURGY OF CAST IRON. 


bars cast flat stood the greatest load, with their side 
which was down when cast being in extension when 
tested, and also that the greatest difference in this re¬ 
spect exists in the round bar. Again I would call at¬ 
tention to the fact that the results in all the flat cast 
bars were very erratic. This Table compares very 
closely in averages with a large number of tests which 
I have made on this point to satisfy myself as to the 
correctness of such results, and they always point in 
one direction. 

A deceptive point which it might be well to notice in 
casting test bars flat is the chance it affords of making a 
test bar record too great a strength for an iron. Take 
a round bar cast flat and test it with its side cast down 
in extension, or as illustrated in Fig. 109, page 490, and 
one can record a greater strength than by any other 
method of casting; but where one desires to record the 
honest and natural strength of an iron, he should use 
the round bar cast on end. And by a comparison of the 
round bar cast on end with those cast flat, as seen by 
Tables 102 and 103, next page, the system which the au¬ 
thor advocates is found to be one which will not permit 
a tester to obtain a greater strength than that which the 
iron truly possesses, nor admit of any jugglery in re¬ 
cording tests. When it is known that one side of a flat 
cast bar can often give 300 to 400 pounds more strength 
than its opposite side, there is surely an opening for 
deception and variable results. The mixture of iron 
charged for the test on next page was all pig metal of 
the analysis seen in Table 104. The analysis of the 
test bars shows the silicon to be reduced ten points and 
the sulphur doubled by re-melting the iron. 


EVILS IN CASTING TEST BARS FLAT 


493 


TABLE IOO.—TRANSVERSE TESTS OF ]/ z " SQUARE BARS CAST FLAT. 


0 J 

fi 

0 V 

Z ~ 

Mode of test¬ 
ing. 

Micrometer 

measure¬ 

ment. 

Deflec¬ 

tion. 

Broke 

at 

in lbs. 

State of 
fracture. 

Strength 
per y 2 " sq. 
in lbs. 

1 

Top up. 

i 4 

•504 

.180 

264 

Sound. 

260 

2 

•509 

.170 

260 

4 4 

251* 

3 

Top down. 

•493 

.160 

240 

44 

233 

4 

4 4 

.526 

.110 

160 

Small flaw. 

145 


Difference in strength extremes of sound bars, 27 lbs. or 11 59 per cent. 


TABLE IOI.—TRANSVERSE TEST OF SQUARE BARS CAST FLAT. 


No. of 
test. 

Mode of test¬ 
ing. 

Micrometer 

measure¬ 

ment. 

Deflec¬ 

tion. 

Broke 

at 

in lbs. 

State of 
fracture. 

Strength 
per sq.in. 
in lbs. 

5 

Top up. 

1.022 

.110 

1,784 

Sound. 

1.709 

6 

4 4 

1.052 

.120 

1,820 


1.645 

7 

Top down. 

1.044 

.120 

1.764 

4 4 

1,618 

8 

44 

1.024 

.100 

1,600 


1,526 


Difference in strength extremes, 183 lbs. or 11.99 P er cent. 


TABLE 102.—TRANSVERSE STRENGTH OF \ x /%" ROUND BARS CAST FLAT. 


No. of 
test. 

Mode of test¬ 
ing. 

Micrometer 

measure¬ 

ment. 

Deflec¬ 

tion. 

Broke 

at 

in lbs. 

State of 
fracture. 

Strength 
per sq. in. 
in lbs. 

9 

Top up. 

1.161 

.160 

2,128 

Sound. 

2,010 

ID 

“ 

1.140 

.150 

1,980 


1,940 

II 

Top down. 

1.171 

.140 

1,996 


1 853 

12 

4 4 

1-131 

.100 

1/82 


1,674 l 


Difference in strength extremes, 336 lbs. or 20 7-100 per cent. 


TABLE IO 3 .—TRANSVERSE TESTS OF 1 ]/%" ROUND BARS CAST ON END. 


No. of 
test. 

Mode of test 
ing. 

Micrometer 

measure 

ment. 

Deflec¬ 

tion. 

Broke 

at 

in lbs. 

State of 
fracture. 

Strength 
per sq in. 
in lbs. 

13 

First flask. 
Cope side 

1.hi 

.110 

1.760 

Sound. 

1.815 

14 

Nowel side 

1.116 

.110 

1.772 


1,812 

15 

Second flask. 
Nowel side 

1.132 

.111 

1 772 

44 

• 

1 761 

16 

Cope side 

1.121 

.110 

1,720 


L 743 














































































494 


METALLURGY OF CAST IRON. 


Difference in strength extremes of two flasks, 72 lbs. or 4.13 per cent., but 
the greatest difference in one flask, tests Nos. 15 and 16, and which is the way 
Table 58 should be shown, is but 1.03 per cent. . 

Tested by Thos. D. West, October 23, 1894, assisted by C. B. Kantner, at 
Sharpsville, Pa. 

TABLE 104. 


Chemical analysis of pig iron charged. 


Chemical analysis of test bars. 


Silicon. 

1.48 


Sulphur. 

Mang. 

.019 

•35 


Phos. 

.097 


Silicon. 

Sulphur. 

Mang. 

Phos. 

1.38 

.038 

•31 

.099 


A study of the tests on page 493 shows that the great¬ 
est difference in one flask of the strength extremes of 
the bars cast on end is but 1.03 per cent., compared with 
11.59, 11 -99 an d 20.07 per cent, found in the bars cast 
flat. It may be well to mention again the fact that all 
the bars were poured out of the same ladle and that the 
flat cast bars were all moulded and cast together in 
one flask, giving them a much better chance to be 
uniform than the bars cast on end, as the latter were 
cast in separate flasks. 

When a system is obtained, where with two bars cast 
together, there will only be three pounds of differ¬ 
ence in their breaking loads per square inch, as is 
found with tests Nos. 13 and 14, Table 103, the author 
has a suspicion that it is about time some were making 
a study of the elements bringing about such close re¬ 
sults.* The difference of 72 pounds between the two 
flasks poured on end, shown in Table 103, could be 
charged to the difference in the fluidity of the metal, 
which existed through lapse of time in pouring the two 
moulds, a quality affecting the strength, etc., of test 
bars more fully defined on pages 372 and 526. Addi¬ 
tional information on casting test bars on end will be 
found on pages 508 and 512. 


* These two tests are given merely to show the close results 
that can be obtained, in a general practice, much better with 
round bars than with square ones. 
















CHAPTER LXVI. 


PHYSICAL TESTS FOR THE BLAST-FUR¬ 
NACE, AND THEIR VALUE.* 

Progress in the science of either making or mixing 
iron requires a study of the physical as well as the 
chemical properties. The importance of a correct sys¬ 
tem for such tests, to make comparison possible be¬ 
tween different furnaces, or the same furnace at differ¬ 
ent times, or with founders, is self-evident. 

The first point to mention is the value of re-melting 
samples of the furnace-casts. The occasional re-melting 
of samples of casts, in a small cupola, cannot but aid 
the advancement of research, and serve as a check on 
chemical analyses, and often as a protection to the fur- 
naceman, by enabling him to learn what the founder 
can do in changing the character of iron after it has 
left the furnace yard. A little cupola will also often 
be convenient for casting small pieces for repairs that 
may be needed between the furnace-casts, or when a 
furnace is out of blast. 

A furnaceman is often not informed of complaints 
concerning his iron until it has been all melted up; 
and then he has generally no remedy other than to in¬ 
spect the castings claimed to have been made from 

* Extract of a revised paper read at American Institute of 
Mining Engineers’ Meeting, Pittsburg, Feb., 1896. 



496 METALLURGY OF CAST IRON. 

the iron complained of. As a founder, I know there 
are ways in which the original character of pig metal 
can be so altered in mixtures as to place upon the 
furnaceman the blame for bad results for which he is 
not justly responsible. In such cases, the remelting 
of a sample by him might often exonerate him.* The 
expense of a small sample cupola need not alarm 
any furnaceman; he can erect one for twenty dollars. 
In fact, the author erected one at the Spearman Fur¬ 
nace, Sharpsville, Pa., January 17, 1896, which did not 
cost six dollars, and took but seven hours’ labor of 
one man from the time ground was broken until the cu¬ 
pola was at work. A cast was made in ten minutes after 
the iron was charged. This cupola was made of an 
old shell, twelve inches in diameter and thirty inches 
long, which was\ lying around in our foundry yard. 
It had been used a few years previously in an industrial 
street parade, for casting horseshoes, which were 
thrown to the people as the wagon went along, the 
blast being furnished by means of an old pair of hand- 
bellows. If iron can be melted under such conditions, 
in such a baby cupola, no one need hesitate to believe 
that it can be conveniently done in a small cupola at a 
blast furnace, where all the blast required can be 
steadily supplied. 

The following Tables 105, 106, and 107, seen on next 
page, give chemical and physical tests of a furnace- 
cast, taken January 18, 1896, at the Spearman furnace, 
Sharpsville, Pa., and is chiefly given to present one 
good form for such records: 

* If founders knew that furnacemen tested their own iron by 
remelting it in a cupola and kept a regular record of all their 
tests, it would have a great tendency to make many investigate 
thoroughly to find whether the fault was not their own before 
m'.ering complaints to the furnacemen. 



PHYSICAL TESTS FOR THE BLAST FURNACE, ETC. 497 


TABLE 105.— PHYSICAL TESTS OF FURNACE IRON TAKEN JANUARY 

l 8 , 1896 . 


No. of 
Test. 

Contrac¬ 

tion. 

Deflec¬ 

tion. 

Strength 

Fluidity. 

Chill. 

Diam’ter 
of Bar. 

Strength 
per sq. in. 

L 

Inch. 

6-64 

Inch. 

0.12 

Pounds. 

2,300 

Inches. 

4 % 

Not 

taken. 

Inch. 

1.194 

Pounds. 

2,054 


TABLE 106.—PHYSICAL TESTS OF CUPOLA-IRON. 


No. of 
Test. 

Contrac¬ 

tion. 

Deflec¬ 

tion. 

Strength 

Fluidity. 

Chill. 

Diam’ter 
of Bar. 

Strength 
per sq. in. 

2 

Inch. 

8-64 

Inch. 

0.08 

Pounds. 

2,220 

Inches, 

5 

Not 

taken. 

Inch. 

I.242 

Pounds. 

1,907 


TABLE I 07 . 

ANALYSIS OF FURNACE-IRON. ANALYSIS OF CUPOLA-IRON. 


Silicon. 

Sulphur. 


Silicon. 

Sulphur 

Per cent. 

Per cent. 


Ter cent. 

Per cent. 

1.02 

0.034 


0.81 

0.056 


Notb; —The number of inches given under “fluidity” in this record is 
directly measured on the fluidity strip, seen at S, in Figs. 121 and 122, pages 
509 and 514. 


The day is past for tolerating- the blind, ignorant 
practice which we foundrymen followed up to about 
1890 in mixing iron. The wonder is that we ever 
“ hit ” what we wanted, when we consider how decep¬ 
tive is the fracture of pig metal as a guide to its true 
“ grade. ” I am aware that up to 1900 a little over half 
our founders kept up with the progress of utilizing 
chemistry in mixing their iron; nevertheless, I say, 
when the furnaceman has done his part, let the founder 
study to do his by calling chemistry to his aid, or else 
get out of the business and stop complaining about 
“bad iron.” There is no “bad iron” in the sense 
some have inferred. All can be utilized in some class 


























































49 8 


METALLURGY OF CAST IRON. 


of work or other. All that is wanted is a knowledge 
of its chemical and physical properties; and when the 
furnaceman and founder understand these as they 
should, pig iron of any “ grade ” or quality need never 
be shipped to the wrong customer. It is simply a 
question of “ carding the car ” right, to have a furnace- 
man clean his yards, and have no complaint about his 
iron, however ‘ ‘ bad ’ ’ he may occasionally make it, if 
he will but give a correct analysis. 

The foundry iron of the analysis in Table 107 is an 
excellent grade to make a machinable, strong casting 
for very heavy work, such as should not be under three 
inches thick in its lightest part, if all pig be used; but 
if the furnaceman gets the wrong shipping card on such 
a car of iron, and some unprogressive founder receives 
the iron, and because it may look “ soft ” or “ open¬ 
grained ’ ’ tries to mix one-third scrap with it, for light 
or medium castings, he abuses the furnaceman, be¬ 
cause his castings crack and come out “ white iron.” 

The cupola illustrated on page 501 is the smallest I 
know of now used for practical purposes. Before 
taking a “heat” out of this small cupola, there was 
but one point that I felt doubtful about, in practice 
with such a small size for the work I intended it to 
perform, and that was, whether it would increase the 
sulphur, by remelting, more or less than is done on 
an average in the large cupolas commonly used. 

Owing to records of cupola mixtures kept at our 
foundry since 1892, or of the analyses of the pig metal 
that go to make exacting work (in which only shop- 
scrap can be utilized), and of the castings produced, 
we are enabled to judge fairly of the increase of sul¬ 
phur by remelting, and found by comparison that the 


PHYSICAL TESTS FOR THE BLAST FURNACE, ETC. 499 

increase in sulphur caused by remelting in the small 
cupola cannot be regarded as any greater than would 
result from remelting in large cupolas. If anything, 
it is a little below what might be expected with fair 
usage. This is due to the iron not remaining in the 
baby cupola as long as in ordinary foundry cupolas. 

I will now proceed to describe a system of testing 
which I installed at the Spearman furnace at Sharps- 
ville, Pa., January 17, 1896, in which the managers 
took great interest and used, without a doubt, with 
much pront to themselves. 

The outfit includes one Olsen transverse testing ma- 
chine of standard make, one cupola, two flasks, and 
chill pig-moulds with a test bar pattern and mould- 
board. An excellent feature of the whole equipment 
is that it need not cost over one hundred dollars, 
including the testing machine. The price of such an 
outfit is no more than a furnace might have to pay for 
freight on one or two cars of condemned iron. 

The cupola. Fig. 111 shows the cupola used. It may 
have a “ drop bottom,” as shown, or it may simply 
rest upon a plain plate, and be tipped by hand to clean 
it out, after the conclusion of heats. The figure itseh 
explains all details necessary to the construction and 
plan of charging the cupola, as seen on next page. 

The cold blast is used so as to be the same as in 
foundry practice. It may require a few trials to find 
out what pressure of blast will give the best results. 
It should not exceed eight ounces pressure at the 
cupola, and will generally be found to work best at 
about six ounces, where two one-inch tuyeres are used. 
Where a low pressure of about four ounces can be 

*If one is inexperienced in managing cupolas, I would advise 
the cupola being 14 inches inside diameter instead of 10 inches, 
as shown, and increasing the tuyere area 30 percent.; that is, 
if a novice desires to use the smallest cupola practical for melting 
small samoles. 



5 °° 


METALLURGY OF CAST IRON. 


well maintained, I would advise the two tuyeres being 
about two inches diameter, and give this plan the pref¬ 
erence over one-inch tuyhres with higher blast press¬ 
ures. 

The cupola should have its bed of coke well on fire 
before the iron is charged, and the latter should be 
distributed evenly all over the surface of the bed, the 
largest pieces being placed in the middle. I have 
melted one-quarter of a common-sized pig all down in 
fifteen minutes from the time it was charged. This 
is mentioned merely to show that the baby-cupola can 
deal very rapidly with chunks of iron. 

The melted iron should be held in the cupola until 
one charge is thought to have been all melted down, 
before it is tapped out. A charge of iron may range 
from 20 to 50 pounds; and several charges may fol¬ 
low, having a layer of coke between them, from four 
to five inches in thickness. For a heat over twenty 
minutes long, some good flux may be advantageously 
used to make a thin slag, which could be run off at 
the tap-hole or at a slag-hole, provided for the purpose, 
about two inches above the level of the tap-hole. To 
start the blast it is usually best to let the lowest 
pressure of blast found permissible with utility left 
on, up to the time that about two pounds of melted 
iron run out of the tap-hole. After this flowing of 
metal, plug up the hole and increase the blast pressure 
a few ounces, so as to bring down the iron quickly, and 
collect it in a good body, which will maintain its fluid¬ 
ity while it remains on the bottom bed before being 
tapped. In letting out the fluid metal, make a large 
hole and have a warm ladle to receive the liquid iron. 

The lining used for the cupola is simply a coating of 





Second charge of coke 


Second charge of Iron. 




First charge of coke. 


First charge of iron. 


Bed of coke. 


— 10 "- 


m 

.■■if: I 


FIG. III. 





























































502 METALLURGY of cast iron. 

fire clay, from three-fourths to one inch thick. It 
could, of course, be lined with fire-brick; the diame¬ 
ter of the shell being proportionately increased. 

The baby-cupola shown is one which experimenters 
and college instructors could well use for giving in¬ 
structions in melting, and will be of value for scientific 
research in all cases where the melting of small 
iron will answer all practical purposes. 

Horizontal chill=mould r and the specimen obtained 
therefrom for testing contraction or chill, is seen in Fig. 
114, page 506. Two sizes of these pig-moulds can be 
used, or only one, as the furnaceman may deem best, in 
following out experiments and tests, as described later 
on. Fig. 115 shows cross-sections through the middle of 
the respective iron moulds; and the larger cross-sec¬ 
tion shows also the tapering-rule, D, applied at the 
end of the mould, to measure contraction. It will be 
noticed that the thickness of these miniature pig 
moulds or chills is one inch. Any variation from 
this thickness would affect the depth of the chill. It 
is, therefore, necessary that care should be exercised to 
have always the same thickness in any standard chill 
pig-mould which might be adopted, that did not ex¬ 
ceed two inches thick. The author does not wish to 
be understood as advising records to be taken of the 
chill from the test-specimens, in cases where very fine 
results are desired, unless note be taken of the fluidity 
of the metal at the moment the chill specimens are 
poured. This is done in the author’s system by means 
of fluidity strips attached to test bars, as at S, in Figs. 

113 and 121, and also in Fig. 122, pages 503, 509 and 514. 

In Fig. 121 a chill piece will be seen at B, which is 
the same as shown at A, Fig. 120, and which is a form 



FIG. 112 















































































504 METALLURGY OF CAST IRON. 

of chill used with the test bars shown, and is three- 
eighths inch thick by three inches long, and made of soft 
steel. Only one side or half of the test bar is here 
considered in measuring a chill for record. For iron 
above 1.25 per cent, silicon and no higher than 0.03 
per cent, in sulphur, this system of obtaining chill- 
records indicated in Fig. 121, will work very satis¬ 
factorily. For iron lower in silicon or higher in sul¬ 
phur, it may be often necessary to have a larger body 
of iron, in order to prevent a specimen being chilled 
all the way through. In such cases, chill-blocks, as 
shown in Figs. 114, 115, and 116, maybe required to 
obtain chill records. Where best value is to be attrib¬ 
uted to the chill records, the fluidity should be noted to 
be the same by eye or by the means shown in Fig. 121. 

Fig. 116 shows a longitudinal section through the 
chill pig-mould of Fig. 114. The well at B is provided 
to prevent cutting the chill in pouring, and to cause 
the bar to pull towards one end in contracting, so as to 
permit the contraction to be readily measured by 
means of the tapering rule, shown at D. This test 
specimen, being twelve inches long, provides a con¬ 
venient length for measuring the contraction, and can 
also be readily broken to note its fracture, or can be 
drilled to obtain samples for analysis. 

The sections in Fig. 115 show that the bottom sur¬ 
face of the chill-mould is round, possessing no corners 
to cause any one part of the specimen to be chilled 
deeper than another, thereby causing internal strains 
and preventing natural contraction of the iron, owing 
to one part of the specimen being thrown into higher 
combined carbon than another. This consideration, 
the author believes, will cause any one making a 


THYSICAL TESTS FOR THE BLAST-FURNACE, ETC. 505 

study of the subject to agree with him in advocating 
the principle of the round chill. 

The tapering rule D, Figs. 115 and 116, is graduated 
on one side, as shown, to measure the contraction in 
the sixty-fourths of an inch. The rule is cut off on 
the small end at a point where it is one-sixteenth of 
an inch in thickness. From this the taper runs up 
two inches, at which point it measures three-six¬ 
teenths of an inch. The distance between the one- 
sixteenth and three-sixteenths points is then equally 
divided by six lines, as shown, so as to read to the one- 
sixty-fourth part of an inch, according as the space of 
contraction will permit the rule to be inserted between 
the chill-mould and the pig specimen, as shown. The 
lines being one-quarter of an inch apart, the scale can 
be easily read; but the rule could, of course, be grad¬ 
uated finer if desired. 

The study of the element of contraction, as it can 
be defined from any pig specimens, Figs. 114, 115 and 
116, will prove very valuable, and, in time, may enable 
a tester to know at a glance, without further research, 
the true “ grade ” of an iron. It can aid the furnace- 
man to detect deception, which is now known to 
exist in the fracture of “ direct metal,” and also to 
learn the true effects of re-melting iron, and what 
metalloids cause the greatest contraction in the iron. 

At E, in Figs. 114 and 116, will be seen a depression 
of about one-quarter of an inch below the top surface 
of the chill-mould. This is to provide means for a 
“ flow-off,” to insure the chill specimens being always 
of the same thickness and prevent any iron running 
over the edges of the mould to retard free contraction 
in any manner. The chill-mould, of course, is set level. 




FIG. 114.—CHILL PIG MOULD AND CASTING. 


FIG. 1 15 .—CROSS SECTION OF SMALL AND LARGE CHILL PIG MOULDS. 



FIG. 116.—LONGITUDINAL SECTION OF CHILL PIG MOULD. 






























































PHYSICAL TESTS FOR THE BLAST-FURNACE, ETC. 507 

By using together the chill-moulds of both sizes, as 
shown in Fig. 115, an excellent illustration will be 
afforded of the reasons why many castings crack or 
pull apart, owing to the work being badly propor- 






Paw i 


. 117.—MOULD READY FOR CASTING. FIG 118.—FLASK AND PATTERN. 

tioned. The small pig test specimen will always show 
a greater contraction than the large one. Such ill re¬ 
sults in cracks, etc., are often placed on the furnace- 
man’s shoulders by claiming that he had sent bad 
iron.” Should a furnace-man not care to use these 














5°8 


METALLURGY OF CAST IRON. 


two sizes of chill-moulds at one 'time, he may, under 
proper conditions, adopt either for constant use. In 
the case of very low grades of iron it might be neces¬ 
sary to adopt the larger chill-mould, since in the 
smaller one the iron might “ go all white.” 

In moulding test=bars for determining transverse or 
tensile strength or the deflection or stretch of an iron, 
the author has advised a very simple design of a flask 
and one which would not require a $4-per-day moulder 
to make the mould. Any intelligent laborer can be 
taught in a very little while how to mould and cast 
such bars successfully; and this can be easily done 
in about two minutes. 

In starting to mould a single test bar, the round test 
bar pattern, L, and the fluidity-strip pattern, U, Fig. 

118, are laid in the recesses of the mould board, Fig. 

119, which has previously been solidly placed. The 
half-flask, H, Fig. 118, is then laid on the mould 
board, rammed up and rolled over, and then the 
“cope” is put on; clamps, at K, Figs. 117 and 120, 
having been put on to hold the two parts close together 
while the cope is being rammed up. Before lifting 
the cope, the test bar pattern L is pulled out end¬ 
wise. The cope is now lifted off; the fluidity-strip 
pattern, U, is drawn out; the cope is put on and 
clamped; and the mould is up-ended ready for casting, 
as seen in Fig. 117. The iron cup, A, Fig. 117, is used 
for the purpose of providing a wide funnel to pour into 
and keep the dirt from passing down with the iron. 
The .slot cut in the iron end of the flask, as seen at E, 
Figs. 117 and 121., is to prevent the iron, as the mould 
fills up, from rising high enough to touch the under 
side of the cup. Should the metal in coming up 


ETC. 509 



PHYSICAL TESTS FOR THE BLAST-FURNACE, 


quickly, as it does, strike the under part of this cup, 
an explosion could occur, making the iron fly in all 
directions. By the plan devised such accidents are 
prevented. 


In cases where the fluidity and chill tests are not de¬ 
sired, and a plain round test bar only is wanted (which, 
for general purposes, will serve many ends), a plain 
round pattern, as at L, Fig. 118, page 507, which in the 


FIG. 121.-SECTION OF MOULD. 


FIG. II9.—PLAN OF MOULD BOARD. 


FIG. 120 ,—CLAMP, CHILL AND 
MICROMETER. 




















METALLURGY OF CAST IRON. 


5 IQ 

rough is one and one-eighth inches in diam., or, in fine 
figures, 1.1284 inches, is all that is required. (Plans for 
casting plain bars are seen on pages 521 and 527.) It is 
well to have the lower end of this pattern made a little 
pointed for about three-fourths of an inch of its 
length, so as not to give a flat sand surface for iron to 
drop on, as in the case where the bar is entirely 
square on the end. In making this strictly plain, 
straight, round bar, the ‘ ‘ cope ’ ’ need not be lifted off, 
as the pattern can be pulled out endwise and the flask 
immediately up-ended, ready for casting (as seen on 
page 507), in less time than it takes to tell it. 

Some might think a pattern rammed up on end in a 
wooden box (see page 527) would answer just as well. 
To do this and not have any swells on the bar requires 
considerable care in ramming the mould. By the plan 
here presented, no more time is required, and there is 
more assurance of unskilled labor obtaining a perfect, 
even, true round bar, free of all swells for its entire 
length, and without a joint mark on it. These are 
essential requirements for a test bar. 

Should it be desired to cast only plain bars, without 
the attached fluidity-strips, the hole in the end of the 
flask, as at N, Fig. 121, could be placed in the center 
of the flask instead of where it is shown in the figure. 

Fig. 112, page 503, gives all the dimensions of the 
single test bar flask shown in Figs. 117 and 118. Fig. 

113 shows a single bar with its fluidity-strip S, as taken 
from a mould. The two projections shown on the bar 
in this figure*, also at A and M, Fig. 103, page 482, con¬ 
stitute plans to be utilized to measure the contraction 
of such bars when they are moulded in jointed flask. 

The simultaneous casting of duplicate test bars, illus- 


PHYSICAL TESTS FOR THE BLAST-FURNACE, ETC. 511 

trated in the next Chapter, shows the design of flask, 
mould board and patterns, with the improved “ whirl 
gate,” which the author designed in the year 1895 for 
running ’ ’ round bars cast on end. The method com¬ 
plete is one which the testing committee of the West¬ 
ern Foundrymen’s Association has used with the 
greatest success in obtaining perfectly solid bars. As 
furnacemen advance in the work of physical tests, 
many may desire to take up questions which the single 
cast bar will not permit of investigation, requiring bars 
cast double, plans for which are cited in the next 
Chapter. Whether the exact plans presented in this 
paper be adopted or not, the principles upon which 
they are based cannot be ignored in the attempt to 
secure true physical tests at the furnace or foundry. 

As a supplement to this Chapter, the author desires 
to again call attention to the importance of the adoption 
by the engineering and foundry world of test bars of a 
size that can establish a fair relation to the chemical 
analysis of iron, or accord with the commercial value 
which usage has given to degrees in its strength. By 
a study of Chapter LXIX., page 528, it will be seen 
that we should not use a bar smaller than of one square 
inch area.* A few are still adhering to the use of one- 
half inch square bars, claiming that they have value in 
giving a ‘ ‘ sensitive test. ’ ’ I would ask such, after having 
studied pages 454, 467 and 484, if they have not drawn 
the wrong conclusions, or if this does not truly mean 
that bars as small as one-half inch square or round are 
so “ sensitive ” to variations in the “temper ” or damp¬ 
ness of sands and degrees in fluidity of metal, as to 
make them very erratic, and hence valueless to be used 
for a comparative test in any one single grade of iron, 
to say nothing about their inability to denote degrees of 
strength in the various grades used in general founding. 

*The American Foundrymen’s Association recommends that 
-bars should not be smaller than one and one-half inches diameter. 
See pages487 to 573. 



CHAPTER LXVII. 


DESIGN OF APPLIANCES AND METHODS 
FOR CASTING ROUND TEST 
BARS ON END. 

To successfully cast round test bars on end, when 

the contraction or fluidity is required in connection 
with the strength and chill of iron, it is essential to 
utilize a flask, etc., designed especially for such work. 
Figures 122, 123, and 124, pages 514 to 516, illustrate 
the design of flask, mould board and patterns with 
the “ whirl-gate ” which the author has designed for 
such a purpose. The test bar patterns and runner are 
illustrated at H, H, and F, Fig. 128, page 524. These 
patterns are also seen at D D and A, Fig. 122, page 514. 
The plan of drawing the patterns out endwise as shown 
avoids the necessity of any rapping of patterns; hence, 
if the mould is fairly rammed and the pins of the flasks 
fit true, it will be evident that few, if any, joints will 
be seen on the bars obtained. 

Moulds cast on end from a parallel pattern will al¬ 
ways be largest at the bottom, owing to the head press¬ 
ure. In making the test bars patterns D D, Fig. 122, 
for the first standard mentioned in Chapter LXIX., as 
an illustration, have them 1.1284 inches in diameter, 
at one end. and 1.0884 at the other. In common 


DESIGN OF TEST BAR APPLIANCES, ETC. 


513 

figures these would measure one and one-eighth 
inches diameter at the large end, and one and three- 
thirty-seconds of an inch at the small end, and of the 
same length seen in Fig. 122. By having a ring at the 
large end, as seen at H, Figs. 122 and 128, the smaller 
end will always be the down one in moulding, and in 
ramming the mould, do so to such a degree of hard¬ 
ness as to permit sufficient straining, due to head press- 1 
ure, to have the castings come out closely alike as to 
size at the bottom and top. 

It is well to mention at this point that should any 
desire to make their test bars in a “ dry-sand ” mould, 
they can readily do so, as there is no wood whatsoever 
connected with the flasks, thus making it practical to 
place the mould in an oven to be dried. For mallea¬ 
ble and steel testing and some special purposes in iron, 
a “ dry-sand ” mould might often be found a very good 
method to adopt. 

Referring to the question of “ chilling,” it cannot but 
be readily seen that as arranged by this system, the test 
bar and the chill must remain in close contact until re¬ 
moved by hand, hence truly recording the full chill¬ 
ing qualities of the iron. At V V, Fig. 126, page 522, 
can be seen the chill used in this system. It is simply 
two half-circles three inches long by three-eighths of 
an inch thick, having a hole drilled in them to fit over 
the pattern tips W W, Fig. 122, These chills are set 
on over the pattern before starting to fill the nowel 
with sand, and in shaking out, must, of course, be 
picked up and used as long as they last. They are 
made of a soft steel shaft, which, after being drilled 
or bored out, are then split as seen. See page 502. 

In the case of very hard grades of iron, such as 


514 METALLURGY OF CAST IRON. 


would go “ white ” in the one and one-eighth round 
test bar at the chill end, when a chill was placed on 
the pattern in ramming the mould which embraces 
such iron as is used in car wheel, chill roll, and gun 
metal—the author would advise the adoption of the 



second or third standard bars of one and five-eighths 
inches and one and fifteen-sixteenths inches in diame¬ 
ter described in Chapter LXIX. If the chill goes all 
“ white ” in the largest bar, he would use the largest 
chill block mould seen in Fig. 115, page 506, as a 



















DESIGN OF TEST BAR APPLIANCES, ETC. 515 

standard. To find the depth of a chill with either of 
these round test bars, hold the chill end (after a bar 
has been tested) over a solid piece of iron and strike it 
as seen in Fig. 125, page 522. A notch being cast in the 
chill end opposite the chill side, as seen at X, Fig. 103, 
page 482, permits the bar being readily broken when 
held as above described. To measure the depth of a 
“chill,” consider only that portion turned “white” 



FIG. I 23 .—NOWEL HALF OF FLASK. 

and the depth it has been chilled is to be defined by 
the eye.* 

Knowing that the degree of fluidity has an effect and 
should, for close, fine work be recorded in order to 
make intelligent comparisons, the author has, in combi¬ 
nation with other new features of this system, provided 
at U U and S S, Fig. 122, an arrangement made pos¬ 
sible with this system, by which we can measure the 

* A plan to take blue prints, etc., of chills is seen on page 588. 








5 l6 


METALLURGY OF CAST IRON. 


height metal will rise in a long, thin wedge. These 
fluidity and life measuring strips are ten inches long 
by three-fourths of an inch wide, as at S, in Fig. 121, 
page 509. The base of these strips measures one-eighth 
of an inch thick, and they run up to a knife edge at 
the top. They are a very sensitive thermometer to de¬ 
note both the fluidity and life of metal, as will be 
found by any one adopting the system. Having the 
fluidity strips poured in a vertical position, as arranged 
in this system in connection with the heavier bodies, 



FIG. I24.—MOULD BOARD, BOTTOM PLATE AND COPE HALF OF FLASK. 


prohibits any forced or unnatural pressure to be ex¬ 
erted, so as to have the strips falsely record the 
fluidity of metal when bars are poured. The metal 
cannot rise in the fluidity strips any faster than in the 
test bar, and hence the strips must have a gradual 
rise. Their measurement can be accepted as practical 
and representing the true fluidity and life of metal 
at the time it is poured. Take such fluidity strips 
and cast them flat (See Fig. 71, page 375); the length 
they “ run ' ’ are largely determined by the way they are 









DESIGN OF TEST BAR APPLIANCES, ETC. 


5 T 7 


poured. Unless great care is used, one may be able to 
make them “run” fully four inches farther than if they 
were poured steadily, whereas, when poured vertically, 
as in the author’s system, if there is a quick dash at 
any time it cannot raise the metal in the fluidity strips 
any faster than in the test bar moulds, thereby causing 
a natural and equal rise to truly denote the metal’s 
fluidity or life at the moment the bars are poured. 

To obtain the contraction of a bar, the distance be¬ 
tween the points or tips V V, Fig. 122, page 514, is 
measured. These contraction tips are accurately cast 
in the mould by means of four projections forming part 
of the flask, two of which are seen at B B, Fig. 123, 
These projections “ chill ” one face of the contraction 
tips V V, thereby giving a clean face to measure from. 
The lower tips are given form by reason of a swell 
being made at the base of the fluidity strips, as will be 
seen at the lower V in Fig. 122. The upper tips are 
formed by having loose tip patterns placed in the re¬ 
cesses of the mould board as seen, in such a manner 
that the uppermost projection B of the flask is on the 
top side of the tip V. By this arrangement full free¬ 
dom for expansion at the moment of solidification is 
permitted, as when this takes place it can extend its 
length downward in the sand forming the bottom of 
the mould. These contraction tips are cast twelve 
inches apart and will be found as arranged to provide 
positive points for obtaining the contraction of any 
‘ ‘ grade ’ ’ of iron. 

At A, Fig. 122, is seen the pattern used for forming 
the pouring basin and runner which leads to the 
“ whirl-gate.” At N is shown how the pouring basin 
and runner look before being broken from the test 


518 metallurgy of cast iron.. 

bars. The reason for the recess seen in the end of 
the flask at E, Fig. 123, is to prevent the metal rising 
above that height at the close of pouring, and thus not 
give the metal a chance .to form a ‘ ‘ fin ’ ’ between 
the top joint of the flask or over the top of its ends at 
H and thus still the more positively insure the casting’s 
own weight pulling the contraction downward in¬ 
stead of the contraction pulling the whole body of the 
casting upward from the bottom of the mould, a fac¬ 
tor which has been the cause of pulling the neck off 
from rolls or causing checks or total separation of parts 
in other kinds of castings. The cross bar in the flask 
is formed, as seen at R, Fig. 123, for the purpose of 
fitting over the runner where it connects with the 
whirl-gate’s basin, to assist the same end just men¬ 
tioned in compelling the contraction to follow a 
natural tendency, and not lifting the whole weight of 
a casting upward, as previously explained. At R R 
and O O, Fig. 122, are seen male and female pins and 
holes, which are arranged as shown so as to insure these 
two sections of the patterns coming together at true 
points, to make it impossible for the action of the ram¬ 
mer to distort them in any way. 

jl In making the “whirl-gates ” seen at T, Fig. 122, 
the operator must so proportion them that the runner 
joined to the basin A, Fig. 122, can carry the iron to 
the inlet of the “ whirl-gates ” as fast as they can de¬ 
liver the metal to the mould, the idea being that as 
soon as the pouring is commenced, with either of the 
three standards, the upright runners are so propor¬ 
tioned that the pouring basin N can be kept full of iron, 
to prevent any dirt passing down the runner through 
the “ whirl-gates ” to the mould. Owing to the small 


DESIGN OF TEST BAR APPLIANCES, ETC. 


5 l 9 


diameter of the one and one-eighth inch test bar, when 
this size bar is used, care must be taken in getting a 
good form to the ‘ ‘ whirl-gate. ’ ’ If that form shown 
in the cut at T, Fig. 122, is closely followed, it will be 
found to give an excellent whirl to the metal as it rises 
in the mould, so as to bring any dirt that may by 
chance flow with the metal into the mould up to the 
top of the casting, and thus cause all test bars to be of 
a sound fracture when broken. The “ whirl-gate ” 
portion of the pattern seen on the left of Fig. 122 is 
made of brass or babbitt metal. The fluidity strips 
UU are cast in the main patterns after they are fin¬ 
ished to the proper size. These fluidity strips can be 
made of any thin piece of wrought iron or steel. To 
strengthen the union of the “ whirl-gate ” portion of 
the pattern with the body of the test bars, brass or 
copper wire is laid in the mould and “ cast in.” The 
size of the “ whirl-gate ” where it joins the one and 
one-eighth inch diameter bar is about one-eighth inch 
in thickness by one inch wide. For the one and five- 
eighths inch, one and fifteen-sixteenths inches diame¬ 
ter bars, make this part of the gate one and one-quar¬ 
ter inches and one and one-half inches wide respect¬ 
ively, maintaining the same thickness of one-eighth 
inch as above shown in the one and one-eighth inch 
diameter bar. 

It will be noticed that iron-perforated bottom-plates 
are used instead of wooden bottom boards to give a 
backing to the “ cope ” and “ nowel ” when up-ended 
in order to prevent the pressure of the metal from 
bursting the mould when cast at such points. To se¬ 
cure these iron bottom plates in place rapidly, strips of 
iron are pivoted at F F, Fig. 124, on the main part of 


5 2 ° 


METALLURGY OF CAST IRON. 


the flask as seen, then, by having a tapering projection 
cast on the bottom plates, as seen at X, Fig. 124, a few 
taps of a hammer on the binding strips F F are all 
that is necessary to secure the bottom plate in place. 

Specifications often call for tests from turned bars. 
The author has arranged for such a test in a very 
simple manner, requiring but little machine work. 
At T, Fig. 127, page 522, is shown a bar having a 
swell cast on it. This can be made from six inches to 
eight inches long and of the diameter necessary to 
cause the “ grade ” of iron used to be readily ma¬ 
chined to 1.128 inches, 1.596 inches or 1.955 inches 
diameter, so as to equal a one, two or three square 
inch area section and conform with the diameter of 
the rough bars given above for unfinished testing. 
The harder the grade of iron the larger diameter 
necessary at T to lessen the influence to chill or cause 
metal to be too hard for turning. But this should not 
exceed one and five-eighths inches diameter with the 
one and one-eighth inches diameter bar. Any iron 
that will be found too hard to be machined in this 
diameter of one and five-eighths inches of a swell, the 
second size or third size of a standard bar could then 
be utilized in having a swell cast on, half an inch 
larger ih diameter than plain rough bars called for. 
Whatever size of a swell is used, the same should be 
constantly used, in order to always have the same 
amount of stock to be turned off a test specimen. 
There are very few grades of iron which can not be 
machined from a body one and five-eighths inches 
diameter. The author has had bars with a swell of 
one and five-eighths inches diameter, cast on one and 
one-eighth inch bars with grades of iron used in mak- 


DESIGN OF TEST BAR APPLIANCES, ETC. 521 

ing- chill rolls, car wheels and gun metal, and found no 
difficulty in having them machined, as shown by the 
turned bars given with the cuts seen on page 472. 
The plan adopted to form these swells is simply to 
place half sections of patterns, as seen at N N, Fig. 
126, over the regular test bar pattern when moulding 
them; then when the cope is lifted off, they are drawn 
separately from the mould. Of course, bars can be cast 
plain their full length and then have a recess about 
three inches long turned into them, instead of follow¬ 
ing the swell plan, wherever this is preferable. 

The flask’s dimensions for casting i/q inch round 
bars, as seen in Figs. 123 and 124, are to be made 
eight and one-half inches by 17 inches inside measure¬ 
ments and four inches deep. To cast two, one and 
five-eighths inches or one and fifteen-sixteenths inches 
test bars, for the second and third standard, mentioned 
page 533, the only change necessary in the whole 
system is to make the flask ten inches to eleven inches 
wide on the inside. If desirable, one flask could be 
made to answer for moulding either the one and one- 
eighth inch, one and five-eighths inch or one and 
fifteen-sixteenths inch diameter bars, simply by hav¬ 
ing a flask 11 inches wide and the holes in the end of 
the flask at H, Figs. 123 and 124, made one and 
fifteen-sixteenths inch diameter, also the one and one- 
eighth inch or one and five-eighths inch test bar pat¬ 
terns to have a swell of one and fifteen-sixteenths 
inches diameter at the point where it would rest, or 
fill the hole H when the bars are being moulded. 

When the strength only is desired, then bars can be 
moulded in any common jointless flasks for the length 
of the bars or by “ bedding ” them in the floor simply 


5 22 


METALLURGY OF CAST IRON. 


by standing patterns on their end tp ram them up on 
the plan illustrated on page 527. In gating and pour¬ 
ing such bars the metal is best dropped from the 
top through a cope, and not allow it to strike the 
sides of the mould, and when two or more bars are 
moulded in one flask, their top pouring “gates” 
should be all con- y 

nected to one 
pouring basin, 
made deep enough 
so as to keep the 
‘ ‘ gates ’ ’ full of 
metal when the 
bars are being poured. By careful work, plain bars can 
y y jy jy be cast on end by this plan that 

will prove sound when broken. 
Plans for single bars are described, 
page 509, and plans for two or 
more plain bars being cast to- 
Fig. 129, page 527. 




FIG. 125. 



il 


FIG. 126 . 


m 


n 


gether are seen 

Let it ever be remembered that, 
at the best, a test bar can only be 
used to make relative comparisons 
in the physical qualities of mixtures, 
and to properly secure these a size 
and form of a bar must be used that 
is not sensitively affected by the 
dampness of a green sand mould, 
and degrees in fluidity of metal. 

This demands that a bar be of round 
form, not less than one and one-eighth inches in diam¬ 
eter, and that such is best cast on end, as is displayed 
by reading Chapters LVI., LIX. and LXV. 





FIG. I27. 
























CHAPTER LXVIII. 


MOULDING, SWABBING AND POURING 

TEST BARS. 

In moulding test bars, every precaution should be 
taken to insure a uniform treatment at all times. The 
sand should always be of the same “ temper,” as far 
as practical, rammed regularly, and of the same 
degree of hardness. The best way to attain this is to 
select some one intelligent man, who will make it his 
business to do all the moulding and casting of test bars 
which shall be required for any one department. The 
end to be sought in obtaining test bars is that they 
should be as near as possible the size of the pattern 
from which they are moulded. There are two factors 
affecting these results. The first is in the ramming 
and “temper” of sand, the second, in drawing the 
patterns. Practice, with some, is such as to require 
more or less jarring or rapping of the patterns before 
they were removed from the mould, and while one 
moulder might not do so to a perceptible degree, 
another might go to the extremes. A system to be 
favored in making comparisons in one's own shop, 
or in the case of one firm with another, should be 
arranged so as to remove any semblance of the ne¬ 
cessity of rapping or jarring patterns. For moulding 
test bars, some space as near the cupola as practical 


5 2 4 


METALLURGY OF CAST IRON. 


should be devoted for this special work and there 
should be a place for every tool and all kept as neat 
and clean as possible. 

After a mould has been rammed up, by the author’s 
system, the round portion of the test bar pattern is 
then pulled out endwise, before the cope is lifted off, 
as seen in Fig. 128, this page. For a handle to draw 
out the test bars endwise, two inches of the patterns 
project outside of the flask as shown at H. The cope 
is then lifted off and the balance of the pattern and 
gates drawn out. 

After all loose 
sand or dirt has 
been blown out 
lightly with a pair 
of bellows, the 
cope is closed on, 
flask clamped, and 
then up-ended 
ready for casting, 
as seen in Fig. 130, 
on page 527. 

In drawing out the test bar patterns endwise, give 
them a half-twist around the mould before starting to 
pull the pattern straight out and they will come very 
easily, as it only requires a pull of from eight to 
twelve pounds at the moment of greatest power to 
draw them out. The pattern should be kept well var¬ 
nished or bees-waxed, so as to prevent the friction of the 
sand wearing them away by a few years’ use or cause 
them to become rough, making a ‘ ‘ dirty mould. ’ ’ When 
the chills at A, Fig. 12c, and V V, Fig. 126, pages 509 
and 522, are used, care should always be taken that they 





































MOULDING, SWABBING AND POURING TEST BARS. 525 

are not rusty or wet from any cause, as this could cause 
an explosion when pouring a mould. It is well to rub 
the chills with a very slight coating of coal oil or good 
machinery oil, where they are not in constant daily use. 

The “ swab ” is something that should not be used in 
moulding test bars, if possible to avoid it, for the rea¬ 
son that if sands are made wetter in some portions of 
a mould than others, it affects the grain of the iron at 
that place, making it different from the rest, and hence 
it may be an element likely to cause erratic results and 
deception in recording the iron’s true strength. If 
the sand is such that a swab must be used, it should 
be done with the greatest caution, especially at that 
part of the mould where the bar will break in being 
tested. The plan of pulling the patterns out endwise 
before the cope is lifted off, as devised by the author 
in his system, makes it unnecessary, with sand at all 
fit to mould test bars in, to use any water on the joint 
of the round part of the bar. The swab might be used 
a little around the gates, but it is best to avoid it if 
at all possible to make a clean, firm mould without do¬ 
ing so. Construct a swab so that the flow of water can 
be under perfect control by the lightest squeeze. To 
insure the stream or drops striking just the part or 
spot desired to be dampened, a good plan is to insert a 
piece of one-eighth inch wire, or long, thin nail, through 
the body of the swab, to project below it about two 
inches, as a guide to direct the stream. By using this 
design of a swab, it will be found that only the exact 
parts desired to be dampened will be affected, and the 
water will not be scattered all over the mould, making 
parts like mud, as is often done by the kind of swabs 
sometimes used. 


5 2 6 


METALLURGY OF CAST IRON. 


In pouring test bars, use only “clean iron.” Never 
take iron having slag or dross floating on top of it. 
Not only should the iron be clean, but a “ clean ladle ” 
should be used and skimmed off before pouring. While 
being poured it should be skimmed so as to prevent 
the oxide, which often rapidly forms on the surface, 
from passing into the mould. 

With the use of round test bars cast on end, an intel¬ 
ligent comparison of one class of metal with another 
will demonstrate that there is a dividing line between 
soft and hard grades as to which would be the strong¬ 
est with “ hot ” or “dull” poured metal. At present, 
that chiefly concerning us here is, at what tempera¬ 
ture are bars best to be poured. As the founder 
chiefly makes tests for comparison, either to test his 
own mixtures or to furnish tests to compare with those 
of competitors, at the request of a middle party, it 
seems but reasonable and best that a temperature be 
maintained that would best conform with that gen¬ 
erally used. I would not advise a metal being too 
“ hot ” or too “ dull,” but something that would aver¬ 
age about four and one-half inches up in the fluidity 
testing tips S and S, Figs. 121 and 122, pages 509 and 514. 

Some founders might say their iron was hotter and 
would run up higher to a fine edge than that. I am 
not disputing these, but I do question whether they 
will always obtain the same high fluidity; and then 
again the iron may come out of the cupola all right, 
but owing to some ‘ ‘ hitch ’ ’ in the moulder getting 
to his “ floor ” ready to pour at some one time, could 
throw them off in their calculations. All elements 
and conditions considered, it is decidedly best to pour 
at a temperature while sure to run and make solid test 


MOULDING, SWABBING AND POURING TEST BARS. 527 


bars, still not so high but the temperature of day in 
and day out can be utilized and all delays allowed 
for, so as to maintain a close uniformity. By endeav¬ 
oring to maintain about the same temperature when 
pouring, it would go a great way in enabling the tes¬ 
ter to attach more value to any comparison he might 
wish to make with his past record, or with others. 

The cut Fig. 129 is a plan for casting plain test bars 
on end, so simple that any foundryman can find flasks, 
etc., to instantly change from casting flat to that of 
casting on end, should he desire 
to do so.* * E, E is the test bar 
mould. B, B are the “gates” con¬ 
necting the pouring basin and the 
moulds. M, pouring well. P, 
cope. R, nowel. For further de¬ 
scription, see pages 510 and 521. 





POURING BASIN 

!«•«/*«!«>««*• 


e • 
n9 








= 1 










FIG. I29. FIG. 130. 

* A few practice pouring bars on end without a cope, merely 
dropping the metal directly into the mould, but such a plan is 
more apt to give defective bars. 








































































CHAPTER LXIX. 


UTILITY OF THE TEST BAR AND STAND- 
ARD SYSTEMS FOR COMPAR¬ 
ATIVE TESTS.* 

Many lose sight of the real utility of test bars. They 

entertain the idea that they will give the actual 
strength, contraction or chill of single or unduplicated 
castings. The only way to obtain positive knowledge 
of these qualities is by making test bars of the same 
thickness and form, if possible, as those of the casting 
for which comparisons were to be drawn. In reality 
this would mean making two castings to be poured at 
the same time with the same iron, and breaking one 
to get the strength, etc., of the other. The true utility 
of the test bar is simply comparative, to define differ¬ 
ences that may exist in mixtures of the various 
“ grades ” of iron, or, in other words, all that the test 
bar will do is to denote the strength, etc., of the iron 
which is poured into the mould; and what the shape 
and size of that mould would do to distort the physical 
qualities of the iron from agreeing with what the test 
bars have recorded, is largely left for experience to 
guess at or comparative tests of broken castings to 
define. 

* Revised paper presented by the author to the Foundrymen’s 
Association, Philadelphia, Pa., December 2, 1896. 



UTILITY OF THE TEST BAR, ETC. 529 

Where there are many duplicates, as in the manu¬ 
facture of car wheels, pipes, etc., we can, by breaking 
a few castings, and test bars that have been cast out 
of the same ladle of iron, obtain a very fair base as a 
standard for future comparisons of what may be ex¬ 
pected in the castings themselves from test bars from 
future mixtures. This is not saying that single cast¬ 
ings made of the same pattern, cast at different times, 
could not have any comparative knowledge imparted 
of their strength, etc., by reason of using a proper test 
bar, cast with the same ladle of iron. If a single cast¬ 
ing stands desired usage and the builder or buyer has 
a record of test bars that was poured of the same iron 
with the casting, he generally can rest fairly assured 
that, if at any other time he should get another cast¬ 
ing made from the same pattern with test bars that 
would show a similar strength, he would have a cast¬ 
ing that would be fairly equal in strength, etc., to the 
first one made. And again, the use of these can often 
prove protection to builders that have machines broken 
by claimants for unjust damages, as, for instance, in 
the case of punch and shear castings, which are often 
broken by reason of carelessness on the part of work¬ 
men or attempts being made by the proprietors to 
utilize a machine above the strains guaranteed. For 
if the builder can prove that previous castings, which 
had tests recorded from test bars, had stood the guar¬ 
anteed strains to compare closely with the casting that 
broke, he cannot be far out of the way in maintaining 
the position that the close comparison of all his test 
bar records justified him in assuming that all castings 
made from that one pattern should be closely alike, 
for the reason that they can be classed under the head of 


530 


METALLURGY OF CAST IRON. 


duplicates similarly as cited above for car wheels, etc., 
the only difference being that these single castings are 
not cast in large numbers and may have months inter¬ 
vening between their production, so that in a practical 
sense castings can, when they are occasionally dupli¬ 
cated, have the test bar records accepted to denote 
their physical qualities in a comparative manner, as 
where any number of castings are steadily or daily 
made from the same pattern. 

The utility of the test bar is being more and more 
recognized and made use of. The author believes 
that within ten years almost all founders and engi¬ 
neers will recognize standards for physical tests.* 
How are we going to be able to make intelligent 
comparisons with our own records or those of others, 
where we find bars as small as one-half inch square 
to two inches square being used, and some of rectan¬ 
gular form and again, it can be said, in all kinds of 
lengths, from a foot up to four feet long, so that we 
practically find hardly two founders using the same 
form or length of a bar, or builders and engineers 
exacting the same character of tests? Some will say 
that the difference in both the length and area of such a 
variety of bars could be computed to strength per 
square inch, in making comparisons. It can be shown 
(see Chapter LXI., page 476) that there is about as much 
difference to be found in formulas for computing such 
variations as is found above. in test bars, and also that 
so eminent and able an authority as Prof. C. H. 

* Many consider that the distribution of the first two editions of 
this work, in connection with the author’s advocacy of round 
bars cast on end in trade papers, is largely responsible for the 
conditions leading up to the recommendation by the American 
Foundrymen’s Association of the proposed standards seen in the 
next chapter. 



UTILITY OF THE TEST BAR, ETC. 531 

Benjamin, of the Case School of Applied Science, has 
shown that formulas used prior to 1901 are unsuited 
and incorrect for figuring the strength of cast beams, etc. 

The prevailing practice of recording tests to-day may, 
in some cases, where test bars not less than of one inch' 
area are used, be accepted as an approximation in so far 
as relates to a firm’s own practice in making com¬ 
parisons for mixture, with permanent hands, but 
should a firm desire to bring in a new manager or 
tester, who has been guided in rulings or records ob¬ 
tained from other shop practice or systems, his past 
experience will prove of very little value to him; 
hence the firm must lose in many ways before the new 
man is enabled to be rightly guided by information 
which he can deduce from his new system. Then, 
again, a manager or tester in making any changes 
from one work to another is also a loser and is sub¬ 
jected to the same inconveniences, etc., just mentioned. 
This shows us that both sides can lose some, say- 

1 

ing nothing as to what is lost by their not being able 
to make intelligent comparisons with the outside 
foundry and engineering world, or with blast furnaces 
from which large quantities of pig metal must and 
should be intelligently purchased. Present practice 
shuts us up like a clam, and makes us dead to all the 
benefits which a standard of physical tests could in¬ 
sure. Progression demands something broader and of 
more correct utility than the practice of 1901 insures. 

In reviewing tests recorded of test bars or castings 
in our engineering text-books of the past, we find the 
practical utility of the same to be largely lost, for the 
reason that there is no base presented upon which to 
formulate mixtures, to duplicate fairly the “ grade ” of 


532 


METALLURGY OF CAST IRON. 


the iron comprising the casting or test bar whose 
strength, etc., has been recorded. If for each test of 
all such castings or test bars we had a standard sys¬ 
tem, we could then by referring to the tests of any 
mixtures in our own practice which had recorded simi¬ 
lar physical qualities in a test bar, be at once in a 
very favorable position to obtain or produce a similar 
casting, having like physical qualities. Some might 
suggest chemical analyses of the castings being re¬ 
corded in order to give a base for making comparisons 
and duplication of like castings. This would work 
admirably in all cases, but of the two methods the 
physical test is often more economical and practical 
for adoption by some founders, for the reason, that 
there are some who can generally conduct physical 
tests, but who cannot maintain a laboratory with its 
chemist, or engage outsiders. Even where founders 
are equipped with laboratories, the physical tests are 
necessary as a “hand-maid,” to tell what is being 
achieved, and still further argue for the advisability 
of a standard system of physical tests. 

If there were no difference in the “ grade ” of an 
iron to make a difference in the hardness, strength, 
contraction, etc., of mixtures or castings, then we 
would not require any physical tests, but when we 
consider mixtures of iron can be made ranging all 
the way from 600 to 4,000 pounds, with one square 
inch area bars twelve inches between supports, it 
plainly illustrates the benefits to be derived by accom¬ 
panying a casting with tests obtained from the same 
ladle or iron by means of suitable test bars, whether 
the strength is obtained by means of transverse or 
tensile tests to make comparisons. 


UTILITY OF THE TEST BAR, ETC. 


533 


Because the i^-inch round bar is large enough not 
to have its carbon severely distorted to make tests 
erratic or belie the ruling power of the percentage of 
iron, etc., in the metal, by the chilling influence of a 
green sand mould, and also because it is not so small 
but that strong grades can often, for rough estimates, 
be used for comparison with weak grades on low-priced 
testing machines, are reasons -why the author used a 
bar as small as 1^6-inch diameter as one standard for 
making comparative tests. Having shown in many 
tests, (page 468) that the i^-inch round bar will fairly 
record degrees in the strength of cast iron to fairly 
agree in a comparative way with the commercial value 
attached to the strengths of the various mixtures rang¬ 
ing from stove plate up through light machinery, heavy 
machinery, car wheel, chill roll and gun metal, the 
author would now refer to two other sizes, i^-inch 
and ill-inches diameter as being also well fitted for 
recognition as standard bars. The two latter sizes of 
bars are best utilized by founders who may make mix¬ 
tures containing less than 1.50 in silicon and above .04 
in sulphur. For those above 1.75 in silicon and below 
.07 in sulphur in the test bar or casting, the 1^/6-inch 
diameter bar will be found to generally record fair 
comparisons in degrees of strength.* 

It is to be understood that while either size of 
the above three proposed standard bars would 
not err much in recording true degrees in the 
strength, deflection, and contraction where com¬ 
parisons are to be made in any one “grade” or in 

* While the i^-inch round bar will answer fairly well for mak¬ 
ing general comparisons in all irons having over 1.75 silicon 
and under .07 sulphur, still the author approves the recommenda¬ 
tions found on page 573, which show that test bars should not be 
smaller than i l / 2 inches in diameter, and cast on end, as such will 
give truer results than the i^-inch round bar in general practice, 
especially in making comparison of the widest ranges in grades. 



534 


METALLURGY OF CAST IRON. 


all of them, the same size bar must be used. One size 
bar cannot be used for one per cent, silicon iron and 
then dropped and another taken up to test percentages 
above or below this. (See Chapter LX\ II., page 520.) 
Whatever size of a common sense bar the testers use, 
in making comparison through any range of work, 
they must stick to that one, and then, if they desire to 
make comparison with outside records that have been 
obtained with standard bars other than the one size 
they use, they would then be compelled to make tests 
with the same size of bars which was used to ob¬ 
tain the outside test. Of course, if a firm desired, they 
could cast the three sizes of bars together, mentioned 
on page 533, with the same ladle of iron, and thus al¬ 
ways have at hand records by which they could make 
comparisons on a moment’s notice, with any outside 
tests that had been obtained with either of the three 
standard sizes of bars mentioned herein.* 

The following Tables, 108 to 113, pages 536 and 537, 
display tests of the author’s proposed three sizes of 
standard bars, accompanied with a chemical analysis 
of the various mixtures shown to still increase their 
value. A study of these Tables (combined with those 
of Chapter LX., page 460), the author believes, will 
sustain him in his advocacy of the i^-inch, iJ4-inch 
and i-tf-inch round test bars as well fitted for and to 
maintain a standard of comparative physical tests. 

The tests presented are obtained from the actual 
mixtures used for pouring castings in the various 
specialties mentioned, and, as seen, are arranged in the 
order of their strength. Double the amount of tests 
were made, but those shown illustrate the relation of 
the different areas in strength per square inch as 
* For three other standards, see pages 573, 577 and 579. 


UTILITY OF THE TEST BAR, ETC. 


535 


well as large numbers could, and make study an easy 
task to readily demonstrate their utility as being suit¬ 
able for standard comparative tests. 

The tests shown are all of solid bars cast on end, 
and they illustrate among other valuable features the 
fact that the two and three square inch area round bars 
record a greater strength per square inch than the one 
square inch area round bars. This series of tests also 
shows conclusively that no one should use a test 
bar smaller than of one square inch area with the 
expectation of making any fair comparisons of 
degrees in the strength, etc., of his irons.* While 
the one square inch area round bar shown does not 
record the high strength for strong metals that the 
larger bars do, it is made very evident that they do 
record degrees of strength fairly accurate for use 
in a comparative test for soft irons or those above 1.50 
in silicon for ordinary testing, a fact also demonstrated 
by the specialty tests as seen in Table 96, page 466, 
showing a gradual rise, in denoting degrees of strength 
in different grades of iron ranging from 1,480 to 3,686 
pounds per square inch. 

The test bars shown in this chapter were cast during 
the month of May, 1896, and were kindly supplied by 
the foundries of the Lloyd-Booth Co., Youngstown, O., 
Philadelphia Roll & Machine Co., A. Whitney & Sons, 
both of Philadelphia, Pa., the Shenango Machine Co., 
and Graff Stove Foundry Co., both of Sharon, Pa. The 
test of “ Bessemer,” Table 113, was cast by the author. 

Tables 108, 110, in, 112, and 113 were tested by Prof. 
C. fi. Benjamin at the Case School of Applied Science, 

*This is in keeping with the recommendations of the A. F. A., 
not to use bars smaller than 1 y 2 inches in diameter. (See next 
chapter.) 



53 6 


METALLURGY OF CAST IRON 


and those of Table 109 by the Riehle Bros., of Philadel¬ 
phia, Pa. The relative strength per square inch is 
obtained by dividing the actual breaking load by the * 
area of the bar, at its point of fracture. (For rule, see 
page 476.) 

TRANSVERSE TESTS OF SPECIALTY IRONS WITH ONE, TWO AND THREE 

SQUARE INCH AREA TEST BARS. 

TABLE I 08 .— CHILL ROLL IRON. 


No. of 
test. 

Diam. of bar. 
Common rule. 

Microm¬ 

eter. 

Breaking 

load. 

Area 
of bar. 

Stre’gth per 
sq. in. in lbs. 

De¬ 

flection. 

1 

1 V ” 

1.140" 

3,250 

1.021 

3,183 

0 105 

2 

1 v "_ 

1-655" 

9,500 

2.151 

4 , 4 U 

0.090 

3 

115-16" 

1.968" 

15,250 

3.042 

5 ,oi 3 

0085 


TABLE IO9.— GUN CARRIAGE METAL. 


No. of 
test. 

Diam. of bar. 
Common rule. 

Microm¬ 

eter. 

Breaking 

load. 

Area 
of bar. 

Stre’gth per 
sq. in. in lbs. 

De¬ 

flection. 

4 

1 %" 

1.122" 

2,780 

.988 

2,812 

0.100 

5 

1 %" 

1.664' 

9,250 

2.174 

4,254 

O.IIO 

6 

1 15-16" 

1.859" 

11,820 

2.714 

4,355 

0.100 


TABLE IIO- CAR WHEEL IRON. 


No. of 
test. 

Diam. of bar. 
Common rule. 

Microm¬ 

eter. 

Breaking 

load. 

Area 
of bar. 

Stre’gth per 
sq. in. in lbs. 

De¬ 

flection. 

7 

1 Vs" 

1.174" 

2,200 

1.082 

2,033 

0053 

8 

1 X" 

1.69/' 

8,100 

2.244 

3,6io 

0.070 

9 

115 16" 

2.008" 

13,500 

3 167 

4,263 

0 072 


TABLE III.'— HEAVY MACHINERY IRON. 


No. of 
test. 

Diam. of bar. 
Common rule. 

Microm¬ 

eter. 

Breaking 

load. 

Area 
of bar. 

Stre’gth per 
sq. in. in lbs. 

De¬ 

flection. 

10 

1 %" 

1.187" 

2,800 

1.1066 

2,530 

0.092 

11 

I S A" 

1.705" 

7,100 

2 282 

3 hi 

0,072 

12 

I 15-16" 

2 001" 

11,900 

3-143 

3 786 

0.079 






























































































































UTILITY OF THE TEST BAR, ETC 


53 ? 


The chemical analyses seen in Table 114 were kindly 
furnished by Dickman & Mackenzie, of Chicago, and 
Dickman & Crowell, of Cleveland. 

Aside from the attention which has been called by 
this paper to various points in the following tests, 
there are two factors which some may be at a loss to 
understand. The first is the break in the gradual in- 


TABLE 112.—STOVE PLATE IRON. 


No. of 
test. 

Diam. of bar. 
Common rule. 

Microm¬ 

eter. 

Breaking 

load. 

Area 
of bar. 

Stre’gth per 
sq. in. in lbs. 

De 

flection. 

13 

1 %" 

1.182" 

2,5-0 

1-097 

2,288 

0.117 

14 

1 S A " 

1 - 745 " 

6,050 

2.391 

2,530 

0.078 

15 

1 15-16" 

2.047" 

9,900 

3-288 

3 ,oii 

0 081 


TABLE 11 3 .—BESSEMER IRON. 


No. of 
test. 

Diam. of bar. 
Common rule. 

Microm¬ 

eter. 

Breaking 

load. 

Area 
of bar. 

Stre’gth per 
sq.in. in lbs 

De¬ 

flection. 

16 

- 1 l A " 

1.175" 

2,150 

1.084 

1,983 

0.100 

17 

1 ¥&" 

1.698" 

5 , 5 oo 

2.263 

2,430 

0.100 

18 

1 15 16" 

1.991" 

8,900 

3.112 

2,860 

0.085 


TABLE 114.— CHEMICAL ANALYSIS. 


Specialty. 

Silicon 

Sulphur. 

Mang. 

Phos. 

Comb. 

Carbon. 

Graph. 

Carbon 

Total. 

ChiT Roll. 

.84 

.071 

.285 

•547 

.61 

2 45 

3x6 

Gun Metal.. 

•73 

•059 

.408 

•453 

.76 

2 47 

3-23 

Car Wheel. 

•78 

.132 

.306 

•3*4 

1.07 

2.36 

3 43 

General 

Machine! y. 

1.30 

•053 

.224 

•433 

.58 

3 3i 

3-89 

Stove Plate. 

2.47 

.094 

.265 

.508 

•19 

4 00 

4-9 

Bessemer 
iron. 

1-52 

• 0.59 

.326 

.083 

•49 

3-73 

4.22 
















































































































































538 


METALLURGY OF CAST IRON. 


crease of strength of the bars, which is displayed 
by test No. 7 being weaker than tests Nos. 4 and 10. 
This is due to the high sulphur in the iron when in 
a small body as of i }6 inches diameter, causing the 
combined carbon to overreach its limit for gradually 
increasing the strength of the i^-inch bars, as shown 
by the break in tests Nos. 1, 4, 10, 13, and 16. Test 
No. 7 is one which strongly emphasizes the wisdom 
of not using bars smaller than inches in diameter 
where the best comparative records are desired, and 
strongly endorses the A. F. A. recommendations, 
seen on page 577. The second factor is that shown by 
the low strength displayed by the “Bessemer” iron 
shown in Table 113. Had the “ iron ” in the Bessemer 
Table 113 been near the percentage seen in Table in, 
for heavy machinery, the strength of the test bars in 
Table 113 should have nearly equalled that of Table 
hi. To note the influence of “iron ” on the strength 
of grades, see Table 37, page 250. 


CHAPTER LXX. 


METHODS OF CASTING TEST BARS FOR 
THE A. F. A. TESTS, COMPILATION 
AND SUMMARY OF RESULTS. 

Prior to about 1890, there had been felt for many 
years the need of tests on cast iron, to give those inter¬ 
ested in its use reliable data of its physical qualities. 
Some work had been done in an effort to obtain records 
that could be used, but before the appointment of the 
American Foundrymen Association’s committee, in the 
spring of 1898, little of practical value had been 
obtained aside from that presented in the first two 
editions of this work. This was due in part to the 
want of a broad experience in founding by experi- 
mentors, and their inability to originate practical 
methods for moulding and casting test specimens in 
the right manner. Some, for one example, started off 
with an elaborate series of tests on one grade of iron 
only, thinking that such would suffice, when in reality 
there are about a dozen grades that should be con¬ 
sidered. Aside from this error the bars were all cast 
flat, and at different pouring temperatures. 

The unreliability of records and systems for testing 
that were pressed on the trade from 1890 to 1899 caused 
the author to labor in every way he could to show 
wherein they erred, and to get others interested suffi- 


540 


METALLURGY OF CAST IRON. 


ciently to help bring about a series of tests that would 
result in giving the engineering and foundry world 
elaborate records of tests, secured through means that 
recognized the different grades, and the importance of 
having all tests in any one grade poured at the same 
temperature. The many tests and papers which the 
author presented demonstrating the errors of past 
methods of testing cast iron, finally resulted in awak¬ 
ening foundrymen and others to the necessity of taking 
some action in the matter; and by the valuable assist¬ 
ance and efforts of Dr. Richard Moldenke, the author 
had the pleasure of seeing the A. F. A. appoint a com¬ 
mittee, at its annual convention in 1898, to obtain such 
tests as were thought necessary. This committee 
consisted of Dr. Richard Moldenke, Messrs. James 
S. Sterling, Joseph S. Seamen, Joseph S. McDonald, 
and the author. The first work of the committee 
was to outline the kind, sizes, and number of test 
bars, and the method of moulding and casting. The 
latter was left wholly to the author, as he had 
stated that he could devise a method whereby a large 
number of different sized test bars, comprising green 
sand and dry sand moulds as desired, could all be cast 
on end, from one ladle of iron inside of thirty seconds, 
thus insuring all bars of any one set being poured with 
metal of practically the same temperature. Some 
doubted the practicability of such an achievement, and 
not until after the first set of 192 bars were cast on 
end from one ladle, within twenty seconds and no bars 
lost, was such recognized as being feasible. This was 
an achievement that should place all the tests of the 
A. F. A. on a plane far above all others ever made; at 
least, all who have noted to any degree the variations 


f 


METHODS OF CASTING TEST BARS FOR THE A. F. A 


541 



A Set of the A. F. A. Test Bars all Poured at same Temperature. 















542 


METALLURGY OF CAST IRON. 


that can exist in the physical qualities of cast iron due 
to variations in the pouring temperatures, must per¬ 
ceive its importance. 

The first cast of the test bars, also the chill and 
fluidity test pieces, are seen at Fig. 131, page 541. 
The patterns and core boxes used are shown in Figs. 
132 to 136. At Fig. 137 is seen one of the malleable 
iron flasks used for making the green sand bars from 
the mould boards seen in Figs. 133 and 134, pages 
544 and 546. The flask, as shown, is clamped and up¬ 
ended ready for lowering into the casting pit, to be 
placed as seen at K, Fig. 138, page 550. The making 
of all these patterns, core boxes, and flasks was 
under the supervision of Dr. R. Moldenke while 
engaged as metallurgist with McConway & Torley 
of Pittsburg, and who donated them to the com¬ 
mittee in the interest of the trade. Doctor Moldenke 
is to be credited with having done most of the work in 
making the patterns and fitting up the flasks. 

The floor space required for casting a full set of 
these bars was eight feet wide by eighteen feet long, 
dug out to make a pit about three feet deep. The 
time required to mould and cast a full set as shown in 
Fig. 131 involved about thirty days’ labor. The first 
set was made under the author’s close supervision; in 
fact, he did considerable of the work. After the pit 
was dug out a level floor was made in the bottom and 
all the green sand moulds and cores were set in place after 
the manner shown in Fig. 138. These set, sand was 
rammed around all the flasks and cores up to the 
level of K and W, Fig. 140, page 552, after which a 
double row of vents was made down each side of 
the cores and flasks. A bed of fine cinders was next 


METHODS OF CASTING TEST BARS FOR THE A. F. A. 543 



FIG. 132. 

Core Box for Moulding Dry Sand, Square and Round Test Bars. Cores are seen at W, page 550. 






544 


metallurgy ok cast iron 



FIG. 133. 

Mould Boards, Gates and Nowel Half of Patterns for Moulding Tensile and Transverse Green Sand Test 
Bars, seen on left of Fig. 131, page 541. 










METHODS OF CASTING TEST BARS FOR THE A. F. A. 545 

laid at the level of K and W, as shown by the black 
dots in Fig. 140. The cinders were also brought out 
to come under the pouring basin A, Figs. 139 and 142, 
pages 552 and 554, after which cores to form the gate 
connection G and risers E, seen in Figs. 138 and 139, 
were placed in position as shown, and sand was then 
rammed up to a level of the top of the cores and 
moulds. To keep the dirt from dropping into the 
mould through the gate holes seen at W, Fig. 138 ; while 
ramming up the pit, boards, to cover the gate holes 
(not shown), were used. After the pit was rammed up 
to a level of the top of the cores and flasks, these boards 
were removed and runner patterns of the form seen 
at Fig. 136, page 548, were then placed over the cores 
to form runners in connection with the main basin A, 
as seen at Fig. 140. This done, plates were set on edge 
as at M, S, and X, after which the inlet plate H was set 
up against the plates S, and plates as at B set against 
its ends after the manner shown. This completed, a 
board 12 inches deep by 15 feet long was braced 11 
inches away from the face of H and the whole bed was 
then rammed up and finished to appear as seen at Fig. 
142. This cut also shows men in position to test lifting 
the inlet plate H by means of levers Y, resting on the 
plate M, to come under lugs N. Stops, as at P, pre¬ 
vented the inlet plate being lifted to any greater height 
than 2^ inches, which insured clean metal only passing 
to the moulds, as when the basin A was filled by the 
ladle U, as seen on page 556, all dirt was confined and 
remained upon the surface of the metal in the basin 
A. Two risers were carried from the two outside 
flasks, as at E, and left uncovered when casting, so 
that when the moulds were filled all surplus metal 


546 


METALLURGY OF CAST IRON 



FIG. 134. 

Mould Board, Gates and Nowel Half of Patterns for Moulding large Transverse Green Sand Test Bars 
seen on left of Fig. 131. page 541. 






METHODS OF CASTING TEST BARS FOR THE A. F. A. 547 

remaining in the basin and runners flowed out readily 
to pig beds having a lower level than the pouring basin 
and runners as seen at C, Figs. 142 and 143, thus leav¬ 
ing the moulds disconnected to be removed singly from 
their casting pits after the gate connections between 
the flasks at G were broken. The basin A being, as 
shown, one foot wide and deep, gives a body of fluid 
iron weighing about three tons, uniform in tempera¬ 
ture. And when it is said that from the moment the 
inlet plate H was lifted to the time the 192 test bars 
and two chill blocks, all weighing when cleaned 3,780 
pounds, were all poured scarcely twenty seconds 
passed and no bars were lost, all will realize the suc¬ 
cess achieved. 

Casting half the bars in dry sand cores was done for 
the purpose of making a comparison between the 
effects of a green and dry sand mould and to give 
greater completeness to the results. The dry sand 
bars were made in cores instead of iron flasks, for the 
reason that it was thought that some of the shops the 
work was assigned to might not be in a position to dry 
the dry sand moulds, but could handle the cores. 

In making the cores it was very desirable to have 
them of a character that would crush easily when the 
bars commenced to contract, as anything preventing 
this might strain the bars internally so as not to give 
a true test. The author adopted the following mixture 

for making the cores: 

1 part lake, ,river, or bank sand, 

3 parts fine silica or crushed sand, 

1 part rosin to 25 parts of sand, 

1 part of flour to 25 parts of sand 
1 part glutrose to 30 parts sand. 

Wet balance with water. 


543 


METALLURGY OF CAST IRON. 




1 

n 


1 

1 

1 

A 





< —- 10 -— > 



• 

^t« 

k' 


X 


— 

R 

/ 


The core mixture mentioned 
possesses very little body to 
stand up in a green state; so 
little that, in making the 
larger cores, rodding was very 
necessary, in order to hold 
the cores together. When 
this mixture is dry the cores 
are exceptionally strong to 
handle, but crush very easily 
when the castings commence 
to contract. To form the 
small neck in the green sand 
tensile test bars as at D, 
Fig. 133, cores made of the 
above mixture were used as 
at F above, Fig. 136. This 
division in the tensile test bars was made for the pur¬ 
pose of giving a long and very short test specimen. 

To obtain the contraction, a device, Fig. 144, page 
557, was arranged so as to punch 34 -inch holes in the 
cores and green 
sand molds. 

These formed 
pins in the 
mould that were 
exactly 12. 
inches apart, 
so that when the 
castings were 
cold the con¬ 
traction could 
be accurately 


fig. 135. 















































methods of casting test bars for the a. f. a. 549 



fig. 137. 

A Flask of Green .Sand Test Bars up-ended, ready for placing in Casting Pit and set as at K, pages 550 and 552. 






550 METALLURGY OF 


CAST IRON. 

























METHODS OF CASTING TEST BARS FOR THE A. F. A. ‘ 55 I 

measured. The few records shown will give a fair 
idea of the ratio of contraction in the large and small 
bars. 

To obtain the chill, the author devised the form of 
test block seen in Figs. 135 and 145, pages 548 and 
559. It was made of the wedge form seen, so that 
the block could be used throughout all the different 
grades. These chilled tests were cast in a core having 
one face part chill and part core, as seen at E' and IT, 
Fig- 135- The chill E' was 1 % inches thick. The 
chill tests, Figs. 145 to 147, pages 559 and 563, chilled 
but slightly at the top points and face, while the chill 
for chilled rolls (not shown) are all chilled, showing 
the hard nature of iron used for chilled rolls, etc. 

The fluidity of the metal was tested by means of 
two fluidity strips inch thick at their base, running 
up to a knife-edge 14 inches long, as seen at X, Figs. 
131 and 135, pages 541 and 548. The principle in¬ 
volved in these fluidity strip tests is the same as de¬ 
scribed for those shown on pages 515 to 517, and they 
serve to show the difference that might exist between 
the fluidity of the various sets of test bars that were 
made and noticed in connection with the tests recorded 
from pages 558 to 570. 

The different kinds of physical tests consisted of 

transverse, deflection, tensile, compression, contrac¬ 
tion, and chill tests. The bars varied in size from 
inch, square and round, increasing *4 inch in size in 
each class up to 4 inches square and 4 J 4 inches round 
for transverse tests, and from inch square and 
round to about 2 inches square and 2^ inches round 
for tensile tests. There were four bars of each kind 
and size made in green sand and four bars of each 


55 2 


METALLURGY OF CAST IRON. 


K 




A*. 




















































































































































































METHODS OF CASTING TEST BARS FOR THE A. F. A. 553 

maae m dry sand, making a total of eight bars of each 
kind. Nearly one-half of the total number was 
finished by being planed if square, and turned if round 
bars, so as to make a comparison between the rough 
cast bars and those which had a trifle more than % 
inch of stock removed from their surface. This was 
done by finishing down the rough bars to correspond 
in size to those of next smaller dimensions as, for 
example, a 4^2-inch rough bar was turned down to a 
4-inch bar, and a 4-inch bar down to a 3%-inch bar, 
and so on until a i-inch rough bar was finished to a 
j 4 -inch bar. This finishing work was chiefly done by 
Dr. R. Moldenke. 

There were 1,601 tests made on 1,229 test bars, not 
counting the chilled pieces and fluidity strips, making, 
roughly, 15 tons of test specimens that were handled. 
To tabulate all the tests as they originally appeared 
in the American Foundrymen’s Association Journals, 
and which were originally designated from A to L, 
making a total of 12 different grades or specialties that 
were tested, would require more space than could be 
justly given here. In an effort to condense the results 
of the A. F. A. tests, and at the same time present a 
fair summary of the whole, the author has omitted, 
excepting in one or two instances, all tests of square 
bars and those of round bars cast in dry sand, which 
reduces the records to 282 tests as shown in Tables 
115 to 126, pages 558 to 570. However, a study of what 
tests are presented in connection with the summary at 
the close of the tables will, the author believes, better 
serve the end for many than were all the original tables 
published, without reduction or comment at his hands. 
The work involved in obtaining these tests can only be 
known by those who have followed up such testing, and 


554 


METALLURGY OF CAST IRON 





METHODS OF CASTING TEST BARS FOR THE A. F. A. 555 

too much praise cannot be accorded Dr. Richard Mol- 
denke, as chairman, for the great zeal, time, and much 
money he has expended in supervising and assisting in 
the accomplishment of this work. We have also to men¬ 
tion as entitled to credit Mr. H. E. Diller and Mr. A. 
Pechstein, who assisted Dr. Moldenke in making 
physical tests and chemical analyses. Credit is also 
due to the respective persons and firms mentioned in 
connection with each table of series A to L, for their 
valuable assistance and kindness in donating the cast¬ 
ings required for the test bars. 

The transverse bars were made about 15 inches long 
and tested 12 inches between supports. Any depres¬ 
sions that the knives might make in the surfaces of the 
round or square bars were noted in recording the 
deflection. Two tests were made, on an average, of 
each kind in all the different sizes of bars. The aver¬ 
ages of the two tests in the original tables of the 
selected bars are recorded in Tables 115 to 126, so as 
to condense the results. The round bars are selected 
in preference to the square bars in compiling Tables 
115 to 126, for the reason that they are better than 
square bars, as is explained in Chapter LXIV. 

The tensile tests in original tables, all of which were 
compiled by Dr. R. Moldenke, were reduced to strength 
per square inch and shown in connection with their 
actual breaking load, but the author has separated these 
so as to give the strength per square inch of the tensile 
tests in the independent Table 126, to be above the 
chemical analyses of the different specialties shown in 
Table 127, both seen on page 570. The actual load at 
which tensile bars broke is shown in the last column of 
casts A, B, C and G to L. The form of bars as turned 
for the tensile tests is seen in Fig. 148, page 583. 

The bars cast in dry sand and green sand showed 



METALLURGY OF CAST IRON. 






METHODS OF CASTING TEST BARS FOR THE A. F. A. 557 

that, as a rule, those cast in the former moulds were 
weaker than in the latter. One hundred tests of dif¬ 
ferent green sand bars, averaging closely alike in size, 
gave an average strength of 33,700 pounds, whereas 
100 tests in dry sand bars gave an average strength of 
31,751 pounds, showing a difference of 1,949 pounds 
or 6 per cent, greater strength for the bars in green 
sand than those in dry sand. The gray iron showed 
the greatest and most uniform difference. There 
were a few casts, in both the chilled and gray iron, in 

which the 
dry sand 
bars aver- 
aged the 
greatest 
strength. 
One of these 
varieties is 
fig. 144. shown in the 

unfinished dry sand bars of Table K 124, page 568. It is 
natural to expect the green sand bars to show the great¬ 
est strength on account of the chilling influence of a 
damp mould. The results of the original tables shown 
in the A. F. A. Journal also show that tests of green 
sand bars are more erratic than those of dry sand, 
although, as a rule, the difference is not sufficient to 
cause the dry sand bar to be given the preference in 
general practice; but where the greatest delicacy in 
testing is desired, by the use of unfinished bars, then 
the dry sand bar would be preferable. The author 
selected the bars from green sand for the Tables 115 
to 126 for the reason that such are almost entirely used 
in general practice, and hence will permit of a better 








558 


METALLURGY OF CAST IRON. 


comparison. Further summary of results, especially 
those illustrated by Tables 115 to 126, are given by 
the author on pages 571 and 574. 


TABLE A-II5.—TESTS OF BESSEMER IRON CAST AT THE THOS. D. WEST 

FOUNDRY CO., SHARPSVILLE, PA. 


Transverse tests of unfin¬ 
ished green sand bars. 

Transverse tests of finished 
green sand bars.* 

Tensile tests of unfin¬ 
ished and finished 
green sand bars. 

No. of 
test. 

Diam¬ 

eter. 

Break’g 

load. 

Deflec¬ 

tion. 

No. of 
test. 

Diam¬ 

eter. 

Break’g 

load. 

Deflec¬ 

tion. 

No. of 

test. 

Diam¬ 

eter. 

Break’g 

load. 

1 

■59 

445 

• 173 

9 

•56 

150 

•305 

16 

■57 

40,440 

2 

1.20 

2,440 

.130 

10 

I-I 3 

1,880 

• 234 

17 

1 13 - 

13.630 

3 

1.78 

6,425 

. 126 

11 

1.69 

5.430 

. 160 

18 

1.71 

28,860 

4 

2.30 

13,965 

.110 

12 

2-15 

10,025 

.114 

19 

2.27 

44.830 

5 

2.92 

24,320 

.101 

13 

2.82 

i 9 T 5 o 

.086 

♦Phil 

ished 

oars. 

6 

3-44 

36,875 

.100 

14 

3-38 

29.340 

.072 

20 

•56 

3.440 

7 

4.02 

58,435 

.090 

15 

3-95 

5 L 985 

.079 

21 

i -13 

13.490 

8 

4 -65 

77,335 

.082 





22 

1.69 

27.520 


*AI 1 the finished bars shown in tests Nos. 9 to 15, as 
well as in all the finished bars in Tables 116 to 126, 
designated by stars, were made of rough bars cast in 
green sand that had a trifle over % -inch of stock turned 
off their surfaces. As an illustration, the tensile bars 
20, 21, and 22 of the above Table 115 were of the 
diameter seen in transverse tests Nos. 10, 11, and 12 
before they were turned 

Compression tests from bars cast in dry sand of 
Table 115 showed a j^-inch cube cut from a rough 
^-inch bar to stand 29,570 pounds, and a *4-inch cube 
taken from the center of a i-inch square bar 20,010 
pounds; from the center of a 2-inch square bar, 13,180 
pounds; 3-inch square, 9,830; and 4-inch square, 9,100 
pounds. 

The iron used for Table 115 or cast A was an all-coke 
pig iron mixture having about 5 per cent, scrap melted 
in a cupola, and is a class of iron used for castings that 












































































































Form of chill tests for The a. f. a 


559 



fig. 


145. —FRACTURE OF CHILL TEST PIECE IN SERIES A. 







5 6 ° 


METALLURGY OF CAST IRON. 


are required to show exceptional service under high 
temperatures or severe sudden heating and cooling, 
causing alternate expansion and contraction strains in 
castings. The fluidity strips ran up full, as shown in 
Fig. 131, page 541. The contraction ranged from .17 
for the ^-inch bars to .03 in the 4-inch bars. The 
chilling qualities of the iron is shown in the test piece, 
Fig. 145, page 559. The chemical analyses of Cast 
A, and all others to Cast L, are shown in Table 127, 
page 570. This first cast A was made under the super¬ 
vision of the author 


TABLE B-Il6.—TESTS OF DYNAMO IRON CAST AT WESTINGHOUSE 
ELECTRIC AND MANUFACTURING CO., PITTSBURG, PA. 


Transverse tests of unfin¬ 
ished green sand bars. 

Transverse tests of finished 
green sand bars.* 

Tensile tests of unfin¬ 
ished and finished 
green sand bars. 

No. of 
test. 

Diam¬ 

eter. 

Break’g 

load. 

Deflec¬ 

tion. 

No. of 
test. 

Diam¬ 

eter. 

Break’g 

load. 

Deflec¬ 

tion. 

No.of 
test. 

Diam¬ 

eter. 

Break’g 

load. 

23 

.58 

210 

. .106 

3 i 

•56 

230 

.306 

38 

.58 

4,440 

24 

I.I 7 

2,300 

.125 

32 

i-i 3 

2,115 

.160 

39 

1.12 

L 5 , 54 o 

25 

1.74 

7,070 

.079 

33 

1.69 

6,120 

• 115 

40 

1.70 

29,140 

26 

2.26 

15,780 

.086 

34 

2.15 

11,065 

.080 

4 i 

2.27 

46,580 

27 

2.86 

3 L 47 o 

.101 

35 

2.82 

24,180 

•095 

*Finished bars. 

28 

3-47 

48,200 

•095 

36 

3-38 

41,485 

•073 

42 

•56 

4.750 

29 

4.01 

73,550 

•093 

37 

3-95 

65,150 

.065 

43 

i-i 3 

15,370 

30 

4.62 

100,120 

.061 





44 

1.70 

27,200 


♦For references to meaning of the star in Tables 116, 117, 120, 121,122, 123 and 
125, see paragraph following Table 115, page 558. 


Compression tests of Table 116 from bars cast in dry 
sand showed a }4-inch cube cut from a rough ^-inch 
square bar to stand 38,360 pounds, and a ^-inch cube 
taken from the center of a i-inch square bar 23,000 
pounds; from the center of a 2-inch square bar, 18,130 
pounds; 3-inch square, 13,790; and 4-inch square, 
12,430 pounds. 
















































































































FORM OF CHILL TESTS FOR THE A. F. A 


56l 



FIG. 146. —FRACTURE OF CHILL TEST PIECES IN SERIES B. 




5 62 


METALLURGY OF CAST IRON. 


The iron used for cast B was soft enough to machine 
readily in sections little more than y 2 inch thick. A 
mixture of coke and charcoal pig iron, with about 40 
per cent, of scrap, was used and melted in a cupola. 
The fluidity strips ran up nearly full. The chilled test 
pieces gave a chill of about 1-16 inch thick, as seen in 
Fig. 146, page 561. This cast was made under the 
supervision of Mr. Jos. McDonald. 


TABLE C-117.—TESTS OF LIGHT MACHINERY IRON CAST AT WESTING- 
HOUSE ELECTRIC & MFG. CO., PITTSBURG, PA. 


Transverse tests of unfin¬ 
ished green sand bars. 

Transverse tests of finished 
green sand bars.* 

Tensile tests of unfin¬ 
ished and finished 
green sand bars. 

No. of 
test. 

Diam¬ 

eter. 

Break'g 

load. 

Deflec¬ 

tion. 

No. of 
test. 

Diam¬ 

eter. 

Break’g 

load. 

Deflec¬ 

tion. 

No. of 
test. 

Diam¬ 

eter. 

Break’g 

load. 

45 

•56 

345 

• 155 

53 

•56 

320 

•305 

60 

•57 

4,740 

46 

1.14 

2,320 

.119 

54 

113 

2.235 

.130 

61 

1 .13 

15,860 

47 

i -75 

6,940 

.085 

55 

1.69 

6,780 

.112 

62 

1.70 

32,020 

48 

2.27 

16,330 

.079 

56 

2.15 

12,495 

.096 

63 

2.27 

48,230 

49 

2.84 

31.030 

.088 

57 

2.82 

26,965 

.085 

♦Finished 

oars. 

50 

3-43 

50,200 

.074 

58 

3-38 

43.150 

.086 

64 

•56 

4 . 34 o 

5 i 

3-98 

72,180 

.067 

59 

3-95 

72.695 

•075 

65 

L13 

14,990 

52 

4-63 

104,470 

.044 





66 

1.69 

26,030 


Compression tests from bars in the above Table 117, 
cast in dry sand, showed a J^-inch cube cut from a 
rough y 2 -inch square bar to crush at 38,500 pounds, 
and a y 2 - inch cube from the center of a i-inch square 
bar at 24,890 pounds; from the center of a 2-inch 
square bar, 18,010 pounds; 3-inch square, 15,950, and 
a 4-inch square, 14,220 pounds. 

The iron used for cast C was of a character to run 
into very thin sections, and yet be soft enough to 
machine readily. About 40 per cent, scrap was used 
in a mixture of coke and charcoal pig iron, melted in 
a cupola. The fluidity strips ran up full. The chill 












































































































FORM OF CHILL TESTS FOR THE A. F. A, 


5-3 



FIG. I47. —FRACTURE OF CHILL TEST PIECES IN SERIES C 






5 6 4 


METALLURGY OE CAST IRON. 


was merely perceptible, as shown in Fig. 147, page 
563. This cast was made under the supervision of Mr. 
Beni. D. Fuller. 

TABLES D & E-Il8.—TESTS OF CHILLED AND SAND ROLL IRON CAST AT 
SEAMEN, SLF.ETH ROLL CO., PITTSBURG, PA. 


Transverse test of unfinished green Transverse tests of unfinished green 
sand bars in cast D. sand bars in cast 1 $. 


No. of test. 

Diameter. 

Breaking 

load. 

Deflection. 

Cbntraction. 

No. of test. 

Diameter. 

Breaking 

load. 

Deflection. 

Contraction. 

67 

•54 

280 

.225 


"75 

•57 

480 

.280 


68 

1.14 

2,460 

O 

00 


76 

1.12 

2,310 

.215 

• 17 

69 

1.74 

11,880 

.270 


77 

I -73 

7,100 

O 

CO 

M 


70 

2.27 

25,130 

.248 

•15 

78 

2.23 

20,650 

.190 

.16 

7 i 

2.79 

48,650 

.220 

.14 

79 

2-93 

44,200 

.180 

•15 

72 

3-39 

84,200 

.200 

.12 

80 

3.26 

61,800 

.190 

.14 

73 

3-94 

126,360 

.170 

.12 

81 

3-92 

99,280 

.180 

• 13 

74 

4 - 5 ° 

201,020 

.160 

.11 

82 

4-33 

128,980 

.150 

.12 


The iron for cast D was used for heavy chilled rolls, 
made from a mixture of cold blast charcoal pig iron 
melted in an air furnace. Transverse bars were cast 
only, for the D and E casts, as no data of commercial 
value could be obtained from tensile tests owing to the 
metal being all white in the sections falling within the 
scope of ordinary testing machines; in fact, the 
fractures of the chill test pieces of the pattern shown 
in Figs. 145 to 147 were white all the way through. 
The fluidity strips ran up full, showing good hot iron. 
The contraction ranged from .28 m the y ?-inch bar down 
to . 11 in the 4-inch bar. The smaller bars of the D 
and E cast were tested by the Pittsburg Testing 
Laboratory, and the heavy ones by the Riehle Brothers 
Testing Machine Co., Philadelphia, Pa. 


































































































COMPILATION op the a. e. a. Tests, etc. 565 

The iron for cast E was used for making sand rolls 
and is of a class similar to Cast D, and must resist 
great bending strains and sudden heating of their sur¬ 
faces. The iron used was warm blast charcoal, melted 
in an air furnace. Though the fluidity strips ran up 
full, some of the small bars were lost owing to the fact 
that such iron chilled quickly in a molten state. The 
chilled test pieces were white throughout the body, 
the same as with Cast D. The contraction ranged 
from . 18 in i-inch bars to . 11 in 4-inch bars. This cast 
was made under the supervision of Mr. J. S. Seamen. 

The iron used for cast 
F consisted of shop scrap 
mixed with old grate bars, 
rusty thin malleable 
scrap, and a white weak 
pig iron, melted in a 
cupola. The mixture 
gave a perfectly white 
fracture up to the 2^/2- 
inch sections, and slightly 
mottled in the center of 
the large bars. It was 
impracticable to machine 
this iron, and hence no 
such tests are shown. The 
fluidity strips did not run up full, showing the effect 
of oxidized iron, the chill extending throughout the 
whole casting of the test pieces. The contraction 
ranged from .28 in the ^-inch bars down to .11 in the 
4-inch bars. 

* This cast and those seen at G, H, I, J, K, and L, pages 566 to 
569, were made under the supervision of Dr. Richard Moldenke, 
at the Pennsylvania Malleable Co.’s foundry, Pittsburg, Pa. 


TABLE F-119.—TESTS OF SASH 
WEIGHT IRON.* 


Transverse tests of unfinished 
green sand bars.* 


No. of test. 

Diameter. 

Breaking 

load. 

Deflection. 

Contraction. 

83 

•55 

170 

.085 

.29 

84 

1 .13 

2,760 

.085 

.26 

85 

1.69 

6,270 

.062 

.20 

86 

2.15 

15,480 

.060 


87 

2.81 

35,900 

•035 

.16 

88 

3-40 

54,420 

.027 

.14 

89 

3-98 

72,870 

.025 

.12 

90 

4 - 5 r 

86.420 

.020 

.11 






















































5 66 


METALLURGY OF CAST IRON. 


TABLE G—120.—TESTS OF CAR WHEEL IRON. 


Transverse tests of unfin¬ 
ished green sand bars. 

Transverse tests of finished 
green sand bars.* 

Tensile tests of unfin 
ished and finished 
green sand bars. 

No. of test. 

Diameter. 

Breaking 

load. 

Deflection. 

No. of test. 

Diameter. 

Breaking 

load. 

Deflection. 

No. of test. 

Diameter. 

Breaking 

load. 

9 i 

•54 

420 

.130 

99 

•56 

370 

.200 

106 

•55 

7.440 

92 

1.13 

2,450 

•125 

100 

i-i 3 

2,040 

.205 

107 

I.I3 

26,830 

93 

1.69 

7,290 

.110 

IOI 

1.69 

6,570 

.170 

108 

1.71 

44, 100 

94 

2.14 

14,880 

.IOO 

102 

2.15 

12,440 

. 140 

109 

2.27 

62,760 

95 

2.84 

27,020 

.097 

103 

2.82 

24,900 

.150 

♦Finished 

aa rs. 

96 

3-38 

47,810 

.080 

104 

3^8 

44 A 30 

.130 

110 

•56 

6,770 

97 

3-97 

70,550 

.080 

105 

3-95 

60,050 

. 120 

hi 

I-I3 

24,480 

98 

4-50 

86,100 

.070 





112 

1.70 

40,060 


The iron used for cast G is such as was intended to 
resist abrasion and sudden increase of temperature on 
its surface, and also to be a good chilling iron. The 
mixture contained cold and warm blast charcoal pig 
iron, some coke pig iron, steel scrap, and old car 
wheels, melted in a cupola. Fluidity strips ran up 
full, and the chill was about ^ -inch deep in the face 
of the chill test pieces. 

TABLE II—121.—TESTS OF STOVE PLATE IRON. 


Transverse tests of unfin¬ 
ished green sand bars. 

I 

| 

Transverse tests of finished 
green sand tars.* 

1 

Pensile tests of unfin¬ 
ished and finished 
green sand bars. 

No. of test. 

Diameter. 

Breaking 

load. 

Deflection. 

No. of test. 

Diameter. 

Breaking 

load. 

Deflection. 

No. of test. 

Diameter. 

Breaking 

load. 

113 

•58 

545 

.130 

121 

•56 

450 

.240 

128 

' -56 

5-443 

114 

1-15 

2,100 

.120 

122 

1-13 

L570 

.200 

I 12 9 

113 

14,400 

115 

1.71 

6,900 

.120 

123 

1.69 

5,100 

. 180 

I 130 

1.71 

34.930 

116 

2.14 

12,880 

.105 

124 

2-15 

10,660 

■175 

131 

2.27 

42,770 

117 

2.83 

20,520 

.100 

125 

2.82 

18,740 

.160 

♦Fin 

ished bars. 

118 

3-39 

42,360 

.090 

126 

3-38 

39,5oo 

.140 

132 

•56 

5.400 

119 

3-98 

64,740 

.090 

127 

3-95 

55.000 

.130 

133 

1.12 

14,920 

120 

4-55 

79,450 

.080 

1 




1.34 

1.69 

30,110 




























































































































































































COMPILATION OF THE A. F. A. TESTS, ETC. 


The iron for cast H was intended for stove plate and 
very light ornamental or plain castings. The fluidity 
strips ran up full and showed the finest impression 
of mould. The mixture contained high phosphorus, 
coke pig iron, and stove plate scrap. No chill was 
seen in the test piece 


TABLE I—122. — TESTS OF HEAVY MACHINERY IRON. 


Transverse tests of unfin¬ 
ished green sand bars. 

Transverse tests of finished 
green sand bars.* 

Tensile tests of unfin¬ 
ished and finished 
green sand bars. 

No. of test. 

Diameter. 

Breaking 

load. 

Deflection. 

No. of test. 

Diameter. 

Breaking 

load. 

Deflection. 

No. of test. 

Diameter. 

Breaking 

load. 

135 

•58 

390 

.220 

143 

•56 

300 

.300 

150 

.64 

7,560 

136 

1-13 

2,490 

.180 

144 

1-13 

2,120 

.270 

151 

1.20 

24,210 

137 

1.70 

7,010 

.140 

145 

1.69 

6,570 

.240 

152 

1.71 

25,740 

138 

2.17 

14,140 

.110 

146 

2-15 

13,200 

.200 

153 

2.28 

39 , 66 o 

139 

2.84 

28,110 

.105 

147 

2.82 

26,440 

.165 

^Finished 

oars. 

140 

3-38 

42,000 

•095 

148 

3-38 

40,000 

•125 

J 54 

•56 

4 , 5 io 

141 

3-97 

58,770 

•095 

149 

3-95 

59,190 

.130 

155 

1.13 

14,120 

142 

4-52 

73 , 4 oo 

.080 





156 

1.69 

24,990 


TABLE J-I 23 .—TESTS OF CYLINDER IRON. 


Transverse tests of unfin¬ 
ished green sand bars. 

Transverse tests of finished 
greep. sand bars.* 

Tensile tests of unfin¬ 
ished and finished 
green sand bars. 

No. of test. 

Diameter. 

Breaking 

load. 

Deflection. 

No. of test. 

Diameter. 

Breaking 

load. 

Deflection. 

No. of test. 

Diameter. 

Breaking 

load. 

157 

•55 

420 

•19 

165 

•56 

300 

•19 

172 

•57 

5,970 

158 

1-15 

2,550 

.18 

166 

1.13 

2,410 

. 16 

173 

1.14 

18,580' 

i 59 

1.72 

5.544 

.16 

167 

1.69 

6,020 

.14 

174 

1.70 

38,300 

160 

2.16 

14,340 

.12 

168 

2-15 

12,880 

.u 

175 

2.27 

62,440 

161 

2.84 

27.770 

• 13 

169 

2.82 

25,300 

.12 

* Finished 

oars. 

162 

3-38 

50,660 

.11 

170 

3-38 

42,420 

.07 

176 

•56 

5,860 

163 

3-93 

66,240 

.08 

171 

3-95 

64,590 

.06 

177 

1-13 

20,070 

164 

4 - 5 i 

78,970 

.07 1 





178 

1.69 

41,920 



















































































































































































































568 


METALLURGY OF CAST IRON. 


The iron used for cast I was made of all-coke pig, 
mixed with machinery scrap, and a little scrap steel, 
melted in a cupola. The mixture was intended for 
heavy machinery castings. Fluidity and chill not 
reported. 

The iron used for cast J contained some steel scrap 
and high sulphur pig, mixed with a No. i foundry coke 
pig iron, melted in a cupola. The mixture was such 
as was desired to give a dense, even-grained iron hav¬ 
ing high wearing qualities, impervious to steam, air, 
and ammonia gases. The iron was quite fluid, and gave 
a chill about 1-16 inch deep in the face of the test 
pieces. 


TABLE K-I24.—TESTS OF NOVELTY IRON. 


Transverse tests of unfin¬ 
ished green sand bars. 

Transverse tests of unfin¬ 
ished dry sand bars.** 

Tensile tests of unfin¬ 
ished bars in green 
and dry sand. 

No. of test. 

Diameter. 

Breaking 

load. 

Deflection. 

No. of test. 

Diameter. 

Breaking 

load. 

Deflection. 

No. of test. 

Diameter. 

Breaking 

load. 

179 

•57 

200 

.14 

r^ 

CO 

* 

* 

•56 

240 

• 17 

i 9 o 

•57 

5,630 

180 

1.13 

1,860 

.11 

**188 

I - I 5 

2,080 

• 13 

196 

I-I 5 

17,860 

181 

1.69 

6,000 

.10 

**189 

1.68 

5.8x0 

.11 

X 97 

1.70 

36,820 

182 

2 -15 

10,910 

.07 

**190 

2.17 

ii, 45 o 

.10 

198 

2.27 

51,180 

183 

2.85 

21,030 

.06 

**191 

2.84 

21,950 

.10 

**199 

.60 

6,850 

184 

3-40 

39 . 5 oo 

.07 

**192 

3-40 

4 i, 57 o 

.07 

**200 

I-I 3 

i 7 , 43 o 

185 

3-96 

54,660 

.04 

**193 

3-97 

56,770 

.05 

**201 

1.70 

33,990 

186 

4-53 

70,020 

•03 

**194 

4-54 

73 , 5 oo 

.04 

**202 

2.26 

45,040 


** As there were no tests of finished bars in green sand in this cast, we sup¬ 
plemented them with tests of unfinished bars cast in dry sand, designated by 
the two stars, as above. 


The iron used for cast K was soft in very thin sections 
and also very fluid, and ran well. The mixture con¬ 
tained high silicon and phosphorus pig iron, stove plate 












































































































COMPILATION OF THE A. F. A. TESTS, ETC. 


scrap, and odds and ends of light junk scrap, melted 
in a cupola. The iron was intended for such work as 
locks, light hardware, and novelty castings, which in¬ 
cludes light electrical supplies. The fluidity strips ran 
up full, and the chill test pieces showed only a slight 
evidence of a chilling effect beyond the closing up of 
the grain. 


TABLE L-125.—TESTS OF GUN IRON. 


Transverse tests of unfin¬ 
ished green sand bars. 

Transverse tests of finished 
green sand bars.* 

Tensile tests of unfin¬ 
ished and finished 
green sand bars. 

No. of test. 

Diameter. 

Breaking 

load. 

Deflection. 

No. of test. 

Diameter. 

Breaking 

load. 

Deflection. 

No. of test. 

Diameter. 

Breaking 

load. 

203 

•57 

520 

.24 

209 

•56 

460 

•35 

216 

•57 

8,740 

204 

1.14 

3.470 

• 17 

210 

1 .13 

3,260 

• 3 i 

217 

I-I 5 

30,460 

205 

1.69 

10,530 

• 15 

211 

1.69 

9,710 

.27 

218 

1.70 ■ 

5 L 490 

206 

2.18 

22,550 

.14 

212 

2-15 

20,480 

.20 

219 

2.27 

69,950 

207 

2.84 

43,730 

.12 

213 

2.82 

41,190 

.19 

*Finished 

bars. 

208 

3-40 

75 , 46 o 

.11 

214 

3-38 

70,770 

.14 

220 

•56 

8,220 

Two 

additional tests be- 

215 

3-95 

98,640 

.10 

221 

I-I 3 

3 L 33 o 

yond range of machine. 

1 




222 

1.69 

47,ooo 


The iron used for cast L was a mixture of the best 
grades of charcoal iron, and some steel and furnace 
scrap iron, melted in an open-hearth steel furnace. 
It is a class of iron that was intended for cannon and 
mortars, special dies, and heavy machinery castings 
requiring good strength and toughness, with uniformity 
of texture and dense granular structure. The iron 
was very hot and gave a Chill of about 1-16 inch thick 
in the face of the chill test pieces. 

Table 126, next page, gives the strength per square 
inch and table 127 gives the analyses, both of which are 
fully explained on page 555. 





































































































57o 


METALLURGY OF CAST IRON 


TABLE 126 .—TENSILE STRENGTH PER SQUARE INCH 
FINISHED BARS IN TABLES 115 TO 


OF UNFINISHED AND 

125. 


Ap’rox. 

Orig. 

Diam. 

A 

B 

C 

G 

H 

I 

J 

K 

L 

•57 

16,000 

16,205 

18,265 

31,000 

21,760 

23,620 

22,960 

21,650 

33 ,6 io 

1.14 

13,700 

15,865 

15.865 

26,560 

14,260 

21,850 

18,210 

17,340 

29,570 

1.70 

12,520 

13,115 

14,170 

19,340 

15,320 

11,290 

16,940 

16,220 

22,680 

2.27 

11,015 

11,405 

12,060 

15.530 

10,610 

9,780 

15,490 

12,700 

17,400 

Kin. 

Diam. 










•56 

13,762 

19,000 

17,386 

27,080 

21,600 

18,040 

23.440 


32,880 

113 

13,490 

15,375 

14,994 

24,480 

14,920 

14,120 

20,070 


3 L 33 o 

1.69 

12,230 

12,525 

IL570 

17,810 

13,580 

11,100 

18,630 


2 J 890 


TABLE I27.—CHEMICAL ANALYSES OF MIXTURES A TO L, 
TABLES II 5 TO 12 5.*** 


Series. 

Class of Iron. 

Silicon. 

Sulphur. 

Manganese. 

Phosphorus. 

G. Carbon. 

C. Carbon. 

T. Carbon. 

At 

Ingot mold . ... 

1.67 

.032 

•29 

•095 

3-44 

•43 

387 

B 

Dynamo frame 

i-95 

.042 

•39 

•405 

3-23 

•59 

3.82 

C 

Light machinery.. 

2.04 

•044 

•39 

CO 

!>■ 

l/.'' 

3-52 

■32 

3-84 

D 

Chilled roll. 

•85 

.070 

•15 

.482 

.06 

2.30 

2.36 

E 

Sand roll . 

.72 

.070 

•17 

•454 

None. 

3-04 

3-04 

l't 

Sash weight. 

•9i 

.218 

.24 

.441 

.20 

2.51 

2.71 

G 

Car wheel. 

•97 

,c6o 

.40 

.301 

3-43 

•74 

4.17 

H 

Stove plate. 

3 - 1 9 

.084 

•38 

1.160 

3.08 

•33 

3-41 

I 

Heavy machinery 

1.96 

.081 

.48 

•522 

2.99 

•33 

3-32 

J ,'f 

Cylinder. 

2.49 

.084 

•47 

•839 

2.99 

.40 

3-39 

K 

Novelty. 

4.19 

.080 

•67 

1.236 

2.85 

•03 

2.88 

L 

Gun metal. 

1.32 

•044 

‘•43 

.676 

2.62 

•50 

3.12 


f All pig iron. J Nearly all burnt scrap. 


*** The above analyses of Table 127 were determined from drillings ob¬ 
tained from 1 " square dry sand bars, taken from the respective casts. 



































































































































































































SUMMARY OF RESULTS OF THE A. F. A. 

SERIES OF TESTS. 


A peculiarity between transverse and tensile tests 

which the A. F. A. series of tests displays, lies in an 
increase of transverse strength per square inch, and a 
decrease of tensile strength, in opposite directions, 
according as areas of cross sections are enlarged. For 
illustration, take the unfinished bar, test No. 2, Table 
i][ 5, page 558, which is 1.20 diameter, giving an area 
of 1.13 inches, and compare its strength per square 
inch in an approximate way with test No. 8, which has 
an area of 16.90 inches, and we find that the larger 
body has 52.7 per cent, greater strength per square 
inch of cross section or area than the smaller body. 
In the case of tensile tests, we find, by an examination 
of Table 126, opposite page, that an average of all the 
1.14 diameter unfinished bars gave 57,250 pounds 
greater strength per approximate square inch than an 
average of the 2.27 diameter unfinished bars. Were 
the bars larger than 2.27 diameter, we would find the 
same principle to hold good. 

The results show that in the construction of ma¬ 
chinery, etc., we may expect greater strength per 
square inch in transverse strains and less in tensile, 
as areas of cross sections are enlarged, and further 
demonstrate that cast iron castings are best con¬ 
structed to stand transverse strains. Why it is that 
the reverse of results should be obtained between 
transverse and tensile tests as shown is largely due 
to the principle “in union there is strength,” being 
applicable to transverse and not to tensile strains 


572 


METALLURGY OF CAST IRON. 


However, if any one should cut a 4^-inch square 
bar of gray iron into i-inch square sections, they 
would find that any one of the sections would then 
stand a much less transverse or tensile load than bars 
of the same area that had been cast 1 inch square of 
the same iron. 

It was a current impression that a large body of 
cast iron is weaker in strength per square inch than 
small ones of the same grade or cast. We find by a 
study of Tables 115 to 126 that this is true only in the 
case of tensile strains. This is the first time that the 
author knows of attention being called to this fact, and 
now that such is publicly done herein it will result, no 
doubt, in changing many practices that have been fol¬ 
lowed, based on the supposition that in the same iron 
large bodies were weaker in strength per square inch 
than small ones. 

The difference between the strength of finished and 
unfinished bars, as shown by the A. F. A. tests, 
demonstrates that where the same thickness of iron is 
removed in finishing test bars, finished bars are less 
erratic in recording strength tests than unfinished 
bars, and that as a rule finished bars are weaker than 
unfinished ones of the same iron. A finished bar that 
will prove stronger than an unfinished one would gen¬ 
erally be due to the outer surface body holding the 
combined carbon higher than was best for strength in 
that grade of iron. This generally occurs only in bars 
that give a great strength in an unfinished as well as 
finished state. To show the difference between unfin¬ 
ished and finished bars, to make an approximate com¬ 
parison, seven tests, A, B, C, G, H, I, and J of the 
1.70 diameter unfinished bars and seven tests of the 


SUMMARY OF RESULTS OF THE A. F. A. TESTS. 


1.69 diameter finished bars (Table 126, page 570), 
some casts having a difference of only .01 diameter, 
show 5,380 pounds or 5.25 per cent, less tensile 
strength than the unfinished bars. Carrying this to 
transverse tests, in calculating the difference of fifty 
tests of each class in similar sizes of bars, we find that 
the finished bars were 212,000 pounds or 16.2 per cent, 
weaker than the unfinished bars. The hard grades 
show a greater difference than the soft grades in this 
respect. Of all the transverse tests in Tables 115 to 
126 there are only about six finished bars that show 
a greater strength than their mates in’the unfinished 
bars. The ^2-inch bars are ignored in all the com¬ 
putations because of their unreliability, as proven by 
the series of A. F. A. and other tests. 

The adaptability of different size bars for compara= 
tive testing is well demonstrated by the A. F. A. 
series of tests. They strongly endorse the author’s 
contention against the use of bars as small as % inch 
square or round, and also show that bars can be too 
large as well as too small. The committee’s report 
recommends bars to be no smaller than 1% inches 
diameter and not larger than 2 x / 2 inches, and all bars 
to be cast on end, which is another point originally 
and strongly advocated by the author. These recom¬ 
mendations are seen on pages 575 and 583. For several 
years the author has realized from experience in test¬ 
ing that a 1 ^2-inch diameter bar was about as small as 
should be used where the best records are desired in 
gray irons, but he accepted the 1^6-inch diameter bar 
shown in other parts of this work for testing, on 
account of its being of an area the most used in the past 
to meet the general conditions of founders who 


574 


METALLURGY OF CAST IRON. 



c 


possess small testing machines, and are not that far 

from the best but that they can in some 
cases be utilized in giving enough ap¬ 
proximate comparative data ot cast iron, 
as is shown in Chapters XLIV., LX. 
and LXIX. 

The utility of the A, F. A. tests is 
not confined to the summary given in 
this chapter. There are other qualities 
which their wide range of tests offer for 
study in obtaining valuable knowledge 
that can be utilized, in some special 
instances, to assist any in the best 
practice of making mixtures of iron, 
grading castings, and testing which 
they set forth. As the tests were 
originally obtained chiefly to derive 
knowledge of what is best to suggest 
for standardizing the testing of cast iron, we will now 
present an extract of the A. F. A. committee’s final 
report as tendered by the chairman, Dr. Richard Mol- 
denke, who is also secretary of the association. 


FIG. 148. 


AN EXTRACT OF THE A. F. A. COMMITTEE’S REPORT 

ON STANDARDIZING THE TESTING OF CAST IRON. 

Your committee desires to state that during the past 
year (1900) sufficient work has been done to warrant a 
final report, based upon the results obtained and the 
conclusions derived therefrom. The magnitude of the 
operations was fully realized at the inception of the 
plan (in 1897), but it was held that the necessities of 
our industry on the one side, and the constantly grow¬ 
ing demands from buyers on the other, fully warranted 












THE A. I'. A COMMITTEE S REPORT. 


575 


every effort of time and trouble given to this impor¬ 
tant subject so vital to our existence. All of the 
members of your committee are active foundrymen, 
heavily burdened with responsibilities which leave 
little leisure for the more interesting pursuits of indus¬ 
trial science, yet ae little time as possible was lost, 
and only those investigations postponed which were 
not actually required for the purposes of this report. 

We must therefore beg that our report be received, 
and our committee on standardizing the testing of cast 
iron be discharged. And we further beg that permis¬ 
sion be granted to the individual members of our 
committee to utilize the mass of material collected, for 
further investigations of interest to the foundry trade, 
and the publication of such results as part of the pro¬ 
ceedings of this association. 

Throughout the whole line of operations only regu¬ 
larly constituted mixtures were used, the balance of 
the heats from which these test bars were cast going 
directly into commercial castings of the classes desig¬ 
nated. The results are therefore entirely comparable 
with daily practice, and are not exceptional cases 
prepared specially for a good showing. For purposes 
of comparison green sand and dry sand bars were 
made side by side, even though the iron, in practice, 
goes into only one of these classes of moulds. It was 
felt that comparison records were wanted just as much 
as specifications for the separate lines of product. For 
this reason also we recommend one standard size of 
test bar for comparative purposes only, each class of 
iron being given its special treatment for the informa¬ 
tion wanted in daily practice, in addition. 

Our studies on the shape of the test bar have resulted 


576 METALLURGY OF CAST IRON. 

in the selection of the round form of cross section, and 
this mainly on the score of greatest uniformity in 
physical structure, the corners of the square bar intro¬ 
ducing elements which become troublesome. It is 
fully realized that the work of testing bars, especially 
transversely, is made more difficult by the adoption of 
the round bar; but, after all, this should only mean the 
taking of proper precautions in measuring the actual 
net deflection — that is, deducting the upper and lower 
indentations in the bar by the knife edges, as ascer¬ 
tained by micrometer measurement, from the deflection 
record. 

There is still a further point of interest in the 
preparation of test bars, and that is the making of 
coupons from which the quality of the casting to which 
they are attached is to be judged. This method is 
used extensively in government work and in the mak¬ 
ing of cylinder castings. The idea of obtaining 
material from the same pour in the same mould as 
part of the casting itself is good enough in theory. 
Unfortunately, however, this direct connection intro¬ 
duces elements of segregation and temperature changes 
in the cast iron which make this test less valuable than 
is generally supposed. At best, the iron which has 
passed through the different parts of a mould before 
entering the space for the coupon will not be repre¬ 
sentative of the whole body, but rather one portion of 
it only. We therefore recommend the method shown 
later on in Fig. 149. The metal can be poured from 
crane or hand ladle clean and speedy, and possesses 
the temperature of the average iron in the casting more 
nearly than the coupon method now practiced. 

Your committee, while giving specifications for the 


THE A. F. A. COMMITTEE’S REPORT. 577 

tensile test of cast iron, is of the opinion that the 
transverse test is the more desirable, and certainly 
within reach of even the smallest foundry. We 
further would suggest to the mechanical engineers of 
this country the desirability of standardizing the speed 
at which the various tests should be performed, and 
also the urgent necessity of studying the impact test 
in its various phases. We deem these questions out¬ 
side of the province of this association, our work being 
the selection of methods for getting at the true value 
of the material we sell, without prejudice or favor. 

In selecting the test bars for the purpose of specifi¬ 
cation, we have followed the cardinal principle of 
selecting the largest cross section for the iron consist¬ 
ent with a sound physical structure, and within the 
range and structural limits of an ordinary testing 
machine. The following are the sizes of bars selected 
for tests as a result of our investigations: 

For all tensile tests a bar turned to .8 inch in diam¬ 
eter, corresponding to a cross section of ^ square 
inch. Results, therefore, multiplied by two, give the 
tensible strength per square inch. 

For transverse test of all classes of iron for general 
comparison, a bar 1 % inches diameter, on supports 12 
inches apart, pressure applied in middle, and deflection 
noted. Similarly for light machinery, stove plate, 
and novelty iron a i^-inch diameter bar; that is to 
say, for irons running from 2 per cent, in silicon 
upward, or from 1.75 per cent, silicon upward where 
but little scrap is in the mixture. 

For dynamo frame, cylinder, heavy machinery, and 
gun metal irons, similarly a 2-inch diameter bar is 
recommended; that is, for irons running from 1.50 to 


578 


METALLURGY OF CAST IRON 



FIG. 149. 

Plan and Elevation View of Casting a few Tensile and Transverse Test 
Bars on end, at one pouring. 




























































THE A. F. A. COMMITTEE'S REPORT. 


579 


2 per cent, in silicon, or where the silicon is lower and 
the proportion of scrap is rather large. 

For roll irons, whether chilled or sand, and car wheel 
metals, a 2^-inch diameter bar is recommended; that 
is, for all irons below 1 per cent, silicon, and which 
may therefore be classed as the chilling irons. This 
would include also all white irons. 

The method of moulding the test bars we would 
recommend is given herewith, and is such as will 
be readily understood by every practical foundryman. 
Both tensile and transverse bars are shown in the same 
flask. The elevation shows the tensile bar at A and 
the transverse one at B. The core C is used with the 
tensile bar in order to ram it on end. The core box is 
seen at Fig. 150. In starting to mould up the bars the 
dried core is set on the bottom board, and then the 
pattern as seen at D placed into the hole in the top of 



FIG. 150. -CORE BOX, TF.NSTLE TEST PATTERN. 


the core and let rest on its bottom. Now ram up the 
bar with green sand in the usual manner. The plan 
shows four bars. This can be modified as desired. 
If no tensile bars are wanted, the core is avoided 
altogether. Two bars may be poured at a time, or 
four, or more, by simply connecting the pouring basin 
E E as shown by the dotted line around G, in which 
case, however, the basin E E should be made much 
smaller. At least three bars of a kind should be made 
for a given test. The accompanying sketches give all 











58 ° 


metallurgy of cast iron. 


the necessary dimensions. It will be noted that the 
bottom of the mould is conical, as seen at I. This is to 
present a sloping surface to the dropping iron and 
help to avoid its cutting the bottom of the mould. 

These bars could be moulded flat and poured on 
their ends by arranging the flask in such a manner that 
pouring gates and basins can be provided on top. 
The extra labor of carrying out this method, in a 
measure counterbalances the making of the core C. 
The only advantage of moulding flat lies in the greater 
certainty of obtaining bars free from swells when made 
by inexperienced moulders. 

The sand should not be any damper than to mould 
well and stand the wash of the iron without cutting, 
blowing, or scabbing. It should be rammed evenly 
to avoid swells, and poured by dropping the metal 
from the top through gates or from the ladle direct 
into the open mould. If the sand will not stand pour¬ 
ing from the top, then pour from the bottom by 
means of whirl gates. If there are more than four 
bars to be poured from the same ladle of iron, where 
it would take more than two minutes’ time in pour¬ 
ing, they should be gated so that the one pouring 
basin can fill all the gates at about the same time, thus 
insuring all bars in a set having the same temperature 
of pouring. After the bars are cast they should remain 
in their moulds undisturbed until cool. 

PROPOSED STANDARD SPECIFICATIONS FOR GRAY 
IRON CASTINGS AND TEST BARS, AS 
ADOPTED BY A. F. A. 

i. Unless furnace iron or subsequent annealing is 
specified, all gray iron castings are understood to be of 


the a. f. a. committee's report. 581 

cupola metal; mixtures, moulds, and methods of 
preparation to be fixed by the founder to secure the 
results by purchaser. 

2. All casting's shall be clean, free from flaws, 
cracks, and excessive shrinkage. They shall conform 
in other respects to whatever points may be specially 
agreed upon. 

3. When the castings themselves are to be tested 
to destruction, the number selected from a given lot 
and the tests they shall be subjected to are made a 
matter of special agreement between founder and 
purchaser. 

4. Castings made under these specifications, the 
iron in which is to be tested for its quality, shall be 
represented by at least three test bars cast from the 
same heat. 

5. These test bars shall be subjected to a transverse 
breaking test, the load applied at the middle with sup¬ 
ports 12 inches apart. The breaking load and deflec¬ 
tion shall be agreed upon specially on placing the 
contract, and two of these bars shall meet the require¬ 
ments.* 

6. A tensile strength test may be added, in which 
case at least three bars for this purpose shall be cast 
with the others in the same moulds respectively. The 
ultimate strength shall also be agreed upon specially 
before placing the contract, and two of the bars shall 
meet the requirements. 

* Note. — The remarkably wide range or values for the ultimate 
strength and modules of rupture which are really good for the 
various classes of iron, precludes the giving of definite upper 
limits in the specifications. It will therefore remain a matter of 
mutual agreement in each case, the requirements of service and 
price per pound paid regulating the mixtures which can be used. 










































































THE A. F. A. COMMITTEE'S REPORT. 


583 



Two required. Test pieces should fit in loosely. 



Cross Section equals y 2 square inch. 

7. The dimensions of the test bars shall be as given 
herewith. There is only one size for the tensile bar 
and three for the transverse. For the light and 
medium weight of gray iron castings the 1^2-inch D 
bar is to be used, for heavy gray iron castings the 
2-inch D, and for chilling irons the 2^-inch D test bar. 
These bars are seen in Figs. 151, 152, and 153. 

8. Where the chemical composition of the castings 
is a matter of specification in addition to the physical 
tests, borings shall be taken from all the test bars 
made, well mixed, and any required determination, 
combined carbon and graphite alone excepted, made 
therefrom. * 

*Note. — There should really be no necessity for this test, for 
the requirements of the physical tests presuppose a given chem¬ 
ical composition. It may, however, sometimes be expedient to 
know the total carbon, silicon, sulphur, manganese, and phos¬ 
phorus of a casting to insure good service conditions. 

































































































5 8 4 


METALLURGY OF CAST IRON. 


9. Reasonable facilities shall be given the inspec¬ 
tors to satisfy themselves that castings are being 
made in accordance with specifications, and, if pos¬ 
sible, tests shall be made at the place of production, 
prior to shipments. 

These somewhat general specifications are doubt¬ 
less capable of being modified, but are presented by 
us to this Association for discussion and possible 
approval in lieu of anything better now in existence.* 

The specifications should certainly be fair to con¬ 
sumer and founder, and, if experience teaches us 
better, can be suitably modified from time to time. 

From the first outline of our plan of casting test 
bars, now known so generally, to the final completion 
of this report we have endeavored to obtain informa¬ 
tion valuable to our industry, and sincerely hope that 
much good may result from this, we think, impartial 
series of conclusions. Respectfully, 

Dr. Richard Moldenke, 
Thos. D. West, 

Jas. S. Stirling, 

Jos. S. Seaman, 

Jos. S. McDonald. 

* This report and specifications were received and unanimously 
adopted by the A. F. A. Convention at Buffalo, June, 1901. The 
committee was tendered a vote of thanks and was discharged. 



CHAPTER LXXI. 


NEW PROCESS FOR BRAZING CAST IRON. 

In the “American Machinist” of March 14, 1901, an 

editorial appears on this subject in which it says: “ If 
the reports of the extreme ease with which this pro¬ 
cess is applied and of its successful results are well 
founded, its discovery marks an important epoch in 
metal working. It was invented by an engineer named 
Poech, and has been thoroughly tested at the Mechan¬ 
ical Technical Testing Institute at Charlottenburg, 
near Berlin. Professor Martens, of this institute, testi¬ 
fies that the iron thus brazed stands the strain like 
new and has not deteriorated under the process. The 
discovery has already been applied by a number of 
prominent engineering firms in Great Britain. 

“ This method of brazing is explained as follows: 
After the surfaces have been cleaned, they are treated 
with a moistened mixture of ‘ ferrofix ’ (which is the 
term applied by the inventor to a metallic oxide, pref¬ 
erably of copper) and a flux such as borax, soluble 
glass, or, better, ‘ borifix, ’ a mixture recently invented 
and patented by the same inventor. The surfaces are 
well covered with borax or borifix, then with strong 
solder such as is used for wrought iron, and then the 
metal is brought to a red heat. A chemical decompo¬ 
sition takes place in which the oxygen of the metallic 
oxide combines with the carbon of the iron to form 


5 86 


METALLURGY OF CAST IRON. 


volatile carbonic acid or carbonic oxide, setting free 
pure metal. This metal covers the surfaces of the 
iron intimately, filling the smallest pores, and facilitates 
the direct and intimate union of the solder with the 
iron. The flux that has been added covers the place 
of the brazing with a vitreous skin, which pre¬ 
vents the oxidation of the iron and the soldering 
metal. 

“The avenues of utility suggested for the new proc¬ 
ess are three: First, repairing cast iron; second, 
putting together large castings (which may be made 
in sections to facilitate moulding and transportation); 
third, brazing cast iron to other metals. In this way 
cast iron can be used in places where wrought iron or 
steel is now employed, by making only that part out 
of the stronger metal which is exposed to special 
strain. While it is hardly to be expected that all pieces 
can be brazed with equal success, it is stated that a gear 
wheel 40 inches in diameter and weighing about 220 
pounds has been satisfactorily repaired in six places in 
hub, spokes, and crown. Moreover, bars 4 inches in 
diameter which have been thus brazed and then broken 
at the same place with a chisel, showed a new line of 
rupture. It is not known that ‘ ferrofix ’ has yet 
reached America, but it can be obtained in Germany 
from Rodolphe Winnike of Berlin. It is also being 
introduced to the trade in England from H. Bertram & 
Co., 28 Queen street, London, E. C., who offer to 
supply full particulars. ’ ’ 


ETCHING.* 


Those who have much to do with chilled irons will 
find the etching test a valuable one. While the prac¬ 
tised eye alone can arrive at the true valuation of what 
the etched surface shows, yet the test is so simple that 
the operation should be understood generally. The 
greatest development has naturally been in the line of 
the steels. First, to distinguish between these and 
wrought iron and thus readily detect fraud and substi¬ 
tution. Second and later, to get at the actual crys¬ 
talline structure in order to judge the quality as 
affected by the heat,, and mechanical treatment the 
specimens had received. 

For cast iron, the polished and etched surface shows 
up the nature of the crystalline structure in the chilled 
portion, and the gradation into gray iron. Where 
experiments are made with additions of steel or 
wrought scrap, the appearance of the etchings is 
a guide to the probable wearing qualities. The samples 
must be first prepared by filing or grinding to get a 
flat surface. Then this is smoothed with successive 
grades of emery cloth until a bright surface is obtained 
which is not too deeply scratched. This polished sur¬ 
face must not be touched with the fingers, as anything 
of a greasy nature prevents the acid from attacking 
the iron. Now the piece is immersed face up in nitric 
acid diluted with ten parts of water. It is best to use 
this mixture cold. A few seconds will suffice to bring 
out the structure. The test piece is then taken out 
and washed thoroughly in running water. 

* This article on etching was contributed to this work by the 
kindness of Dr. Richard Moldenke. 



5 88 


METALLURGY OF CAST IRON. 


If it is desired to print from the etching, more care 
must be taken. The specimen should be perfectly 
flat, — if possible, with two parallel surfaces. The 
etching-solution used is weaker — say one nitric acid, 
and fifty or even one hundred water. A small brush 
can be used to advantage to run over the top of the 
specimen to remove the spent acid and keep a good 
circulation. This makes the etching process slow but 
uniformly even. The result, however, is really fine, 
and the novice will do well to practice on wrought 
iron, which gives beautiful etchings. In printing 
from these etched specimens an ordinary printer’s 
roller, not too heavily charged with ink, is used, and 
the paper must be a superfine calendered variety which 
is perfectly smooth. 


TABLES OF UTILITY FOR FOUNDING 


TABLE 128.—NET WEIGHT OF SAND PIG IRON PER TON OF 2,263 LBS. 


Net. 

Gross. 

Net. 

Gross, 

Net. 

Gross. 

1 

2,268 

35 

79,38o 

69 

156,492 

2 

4.536 

36 

81,648 

70 

158,760 

3 

6,804 

37 

83 916 

71 

161,028 

4 

9,072 

38 

86,184 

72 

163.296 

5 

n ,340 

39 

88,452 

73 

165,564 

6 

13,608 

40 

90,720 

74 

167,832 

7 

15,876 

4 i 

92,988 

75 

.170,100 

8 

18,144 

42 

95,256 

76 

172,368 

9 

20,412 

43 

97,524 

77 

174,636 

10 

22,680 

44 

99,792 

78 

176,904 

11 

24,948 

45 

102,060 

79 

179,172 

12 

27,216 

46 

104,328 

80 

181,440 

13 

29,484 

47 

106,596 

81 

183,708 

14 

3 L 752 

48 

108,864 

82 

185,976 

15 

34,020 

49 

111,132 

83 

188,244 

16 

36,288 

50 

113,400 

84 

190,512 

17 

38,556 

5 i 

115,668 

85 

192,780 

18 

40,824 

52 

117,936 

86 

195,048 

19 

43,092 

53 

120,204 

87 

197,316 

20 

45 , 36 o 

54 

122,472 

88 

199,584 

21 

47,628 

55 

124,740 

89 

201,852 

22 

49,896 

56 

127,008 

90 

204,120 

23 

52,164 

57 

129,276 

9 i 

206,388 

24 

54,432 

58 

I 3 L 544 

92 

208,656 

25 

56,700 

59 

133 812 

93 

210,924 

26 

58,968 

6d 

136,080 

94 

213,192 

27 

61,236 

61 

138,348 

95 

215,460 

28 

63.504 

62 

140,616 

96 

217,728 

29 

65,772 

63 

142,884 

97 

219,996 

3° 

68,040 

64 

145,152 

98 

222,264 

3i 

70,308 

65 

147,420 

99 

224,532 

32 

72,576 

66 

149,668 

IlO 

226,800 

33 

74,844 

67 

151,956 


'f' 

34 

77,112 

68 

i 54. 22 4 

































59° 


METALLURGY OF CAST IRON. 


TABLE I2Q. —NET WEIGHT OF CHILLED PIG IRON PER TON OF 2240 LBS. 


Net. 

Gross. 

Net. 

Gross. 

Net. 

Gross. 

Net. 

Gross, 

1 

2,240 

26 

58,240 

5 i 

114,240 

76 

170,240 

2 

4,480 

27 

60,480 

52 

116,480 

77 

172,480 

3 

6,720 

28 

62,720 

53 

118,720 

78 

174,720 

4 

8,960 

29 

64,960 

54 

120,960 

79 

176,960 

5 

11,200 

30 

67,200 

55 

123,200 

80 

179,200 

6 

i 3 - 44 o 

3 i 

69,440 

56 

125,440 

81 

181,440 

7 

i5,6So 

32 

71,680 

57 

127,680 

82 

183,680 

8 

17,920 

33 

73,920 

58 

129,920 

83 

185,920 

9 

20,160 

34 

76,160 

59 

132,160 

84 

188,160 

10 

22,400 

35 

• 78,400 

60 

134,400 

85 

190,400 

n 

24,640 

36 

80,640 

61 

136,640 

86 

192,640 

12 

26,880 

37 

82,880 

62 

138,880 

87 

194,8S0 

13 

29,120 

38 

85,120 

63 

141,120 

88 

197,120 

14 

3 L 36 o 

39 

87,360 

64 

H 3 , 36 o 

89 

199,360 

15 

33 . 6 oo 

40 

89,600 

65 

145,600 

90 

201,600 

16 

35.840 

4 i 

91,840 

66 

147,840 

9 i 

203,840 

17 

38,080 

42 

94.080 

67 

150.080 

92 

206,080 

18 

40,320 

43 

96,320 

68 

152,320 ‘ 

93 

208,320 

19 

42,560 

44 

98,560 

69 

154,560 

94 

210,560 

2 D 

44,800 

45 

100,800 

70 

156,800 

95 

212,800 

21 

47,040 

46 

103,040 

7 i 

159,040 

96 

215,040 

22 

49,280 

47 

105,280 

72 

161,280. 

97 

217,280 

23 

5 L 52 o 

48 

107,520 

73 

163,520 

98 

219,520 

24 

53 , 76 o 

49 

109,760 

74 

165,760 

99 

221,760 

25 

56,000 

50 

112,000 

75 

168,000 

100 

224,000 



























METALLURGY OF CAST IRON. 591 

TABLE I 30 . INTERNATIONAL ATOMIC WEIGHTS SELECTED BY GERMAN 

CHEMICAL SOCIETY, 1902 . 


Aluminum, A 1 . 


Antimony, Sb. 


Arsenic, As. 

• 75 -o 

Bismuth, Bi. 


Bromine, Br. 


Cadmium, Cd. 


Calcium, Ca. 


Carbon, C. 


Chlorine, Cl. 

• 35-45 

Chromium, Cr. 


Cobalt, Co. 

. 59.0 

Copper, Cu. 

- 63.6 

Fluorine, F. 

. 19.0 

Gallium, Ga. 


Gold, Au. 

. 197.2 

Hydrogen, H. 


Iodine, I. 


Iridium, Ir. 

. 193.0 

Iron, Fe. 

• 55-9 

Lead, Pb. 


Magnesium, Mg. . . . 

. 24.36 


Manganese, Mn. 

.... 55 -o 

Mercury, Hg. . 


Nickel, Ni. . . 

.... 58.7 

Nitrogen, N. . . 


Oxygen, O. . . 


Palladium, Pd. 

.... 106.5 

Phosphorus, P. 

• • • • 31.0 

Platinum, Pt. . 

.... 194.8 

Potassium, K. . 


Silicon, Si. . . . 


Silver, Ag. . . 

.... 107.93 

Sodium, Na. . . 

... 23.05 

Sulphur, S. . . 


Tin, Sn. 


Tungsten, Wo. . 


Uranium, Ur. . 

.... 238.5 

Vanadium, V. . 


Yttrium, Y. . . 


Zinc, Zn. . . . 


Zirconium, Zr. . 



TABLE 131 .—CONVERTING DEGREES FAHRENHEIT TO DEGREES 
CENTIGRADE (DEGREES C.= (DEGREES F-32) 5 


Fahr. 

Cent. 

Fahr. 

Cent. 

Fahr. 

Cent. 

Fahr. 

Cent. 

100 

37-8 

1000 

537-8 

1900 

1037.8 

2800 

T 537-8 

200 

93-3 

1100 

593 3 

20^0 

1093-3 

2900 

LS 943 

300 

148.9 

1200 

648.9 

2100 

1148.9 

3000 

1648.9 

400 

204.4 

1300 

704.4 

2200 

1204.4 

3100 

I 7 r 4-4 

500 

260 0 

1400 

750.0 

2300 

1260.0 

3200 

1760.0 

600 

315-6 

1500 

815.6 

2400 

IU 5-6 

33 oo 

1815.6 

700 

371 l 

1600 

871.1 

2500 

1371.1 

34 co 

1871.1 

800 

426.7 

1700 

926.7 

2600 

1426.7 

3500 

1926.7 

900 

482.2 

1800 

982.2 

2700 

1482.2 

3600 

1982.2 


“Absolute Zero ” of the Air Thermometer is equal— 460 ° Fahrenheit. 

“ “ “ “ “ — 273 . 5 ° Centigrade. 













































































59 2 


METALLURGY OF CAST IRON. 


HEAT UNITS. 

There are two units in use for measuring the quantity of heat 
contained in matter. 

The first is the British thermal unit , and which is the amount 
of heat required to raise i pound of water i° Fahrenheit. 

The second is the calorie , and which is the amount of heat 
necessary to raise i kilogram of water i° centigrade. 

The calorie is used in Germany, France and other countries 
using the metric system of weights and measures. 

TABLE 132.—HEAT OF COMBUSTION. 

Heat developed by combustion of one pound of the following 
substances: 


Substance. 

Calories. 

Substance. 

Calories. 

Anthracite. 

7,200 to 8,200 

Lignite. 

4,500 to 6,000 

Alcohol. 

7 .i 85 

Manganese to MnO.. 

1,723 

Carbon to CO. 

2,404 

Marsh Gas. 

13,063 

Carbon to CO2. 

8,o8o 

Olifient Gas. 

11,858 

Coal—bituminous ... 

6,500 to 9,000 

Olive Oil. 

9,860 

Coke. 

6.400 to 8,000 

Petroleum. 

10,600 to 11,000 

Diamond. 

7,879 

Phosphorus—P2O5.... 

5,747 

Ether. 

9,028 

Silicon. 

7,830 



Hydrogen. 

34,462 

Sulphur to SO2. 

2,162 

Iron to FeO. 

L 35 I 

Sulphur SO3. 

2,868 

Iron to Fe2. O3. 

1,887 

Wood. 

2,500 to 4,000 


TABLE 133.—COLOR NAMES FOR HIGH TEMPERATURES. 

By Maunsel White and F. W. Taylor. Read at the December, 1899, meeting of 
the American Society Mechanical Engineers. 


NAME OF COLOR. Temperature. 

C. F. 


Dark blood red, black red. 
Dark red, blood red, low 

red. 

Dark cherry red. 

Medium cherry. 

Cherry, full red. 


990 

56G 1050 

635 ”75 
1250 

746 1375 


NAME OF COLOR. Temperature. 


Light cherry, bright cher¬ 
ry, light red.. 

Orange. 

Light orange. 

Yellow. 

Light yellow. 

White. 


0 . 

843 

899 

94 1 
996 

Ic 79 

1205 


F. 

1550 

1650 

U25 

1825 

1975 

2.00 

























































































METALLURGY OF CAST IRON 


593 


TABLE I34. — “MELTING POINT OF METALS.” 


Name. 

Cent. 0 

Fahr.° 

Authority 

Rem arks. 

f 

Aluminum 

655 

1211 

Berthelot 

1900 — 1901 

Antimony 

630.6 

1167.1 

Holborn & Day 

1900 — 1901 

Bismuth 

270 

518 

Callendar & Griffiths 

1898 — 1899 

Cadmium 

321.7 

611 

Holborn & Day 

1900 — 1901 

Copper 

1084.1 

1983 4 

II It 

In reducing atmosphere J 1900 to 

Copper 

1064.9 

1948.8 

it 44 

In oxidizing atmosphere j 1901 

Gold 

1064 

1947.2 

it 44 

1900 — 1901 

Iridium 

1950 

3542 

Violle 

1877 — 1879 

Iron 

1600 

2912 

Pictet 

Pure— wrought 

Lead 

326.9 

620.4 

Holborn & Day 

1900 — 1901 

Magnesium 

633 

1171 

Heycock & Neville 

1895 — 1899 

Manganese 

1850 

3362 

Van der Weide 

1879 

Mercury 

—38.5 

—37.3 

Regnault 

1847 (7) 

Nickel 

1450 

2642 

Pictet 


Osmium 

3000 -f 

5432 + 

Deville & Debray 


Palladium 

1580 

2876 

Holborn & Wien 

1895 (?) or later 

Platinum 

1780 

3236 

44 It 

1895 (?) or later 

Rhodium 

2000 

3632 

Pictet 


Ruthenium 

2000 + 

3632 + 

Deville & Debray 


Silver 

961 5 

1762.7 

Holborn & Day 

In reducing atmos. 1900-1901 

it 

955 

1751 

a a 

In oxidizing “ ill defined 

Tin 

232.1 

449.8 

Stansfield 

1898 

Zinc 

419 

786 

Heycock & Neville 

1895 — 1899 


NOTE:—Berthelot, Holborn & Wien and Holborn <fe Day made their determinations with thermo 
electric pyrometers. 

Callendar & Griffiths and Hejcock & Neviile used resistance pyrometers. 

Stansfield used a recording thermo couple. 

All temperatures determined after 1895, as given above, are accepted as trustworthy. 

Some claim that the data furnished by Pictet and Deville & Debray are too high, and should be 
verified by further researches. 

TABLE 135.—RELATIVE CONDUCTIVITY OF METALS FOR HEAT AND 

ELECTRICITY. 


Metal (in vacuo). 

Heat. 

Elec¬ 

tricity. 

Bilver. 

100. 

100. 

Copper. 

74 - 

77-43 

Gold. 

54 8 

55-19 

Zinc. 

28.1 

27 39 

Brass. 

24 0 

22.0 

Tin. 

15-4 

H -45 


Metal (in vacuo). 

Heat. 

Elec¬ 

tricity. 

Iron. 

n -9 

14.44 

Steel. 

10.3 


Lead. 

7-9 

7-77 

Platinum . 

9-4 

10.53 

German Silver. 

6-3 

6. 

Bismuth. 

1.8 

1.8 


TABLE 136-^SPECIFIC GRAVITY AND WEIGHT PER CUBIC INCH—METALS. 


Metal. 

Sp. Grav. 

Weight 
per cu. 
in. lbs. 

Aluminum. 

2.56-2.67 

.094 

Antimony. 

6.71 

.242 

Bismuth. 

99 

•357 

Brass. 

7.8-8 8 

.281-310 

Bronze. 

8.7 

• 3 X 4 

Copper, cast. 

8-79 

•317 

Copper, wire. 

German Silver. 

889 

.322 

Gold, hammered... 

19.40 

.701 

Gold, cast. 

19 26 

.697 

Iron,cast. 

7.20 

.260 

Iron, bar. 

7-79 

.282 

Lead.. 

H -37 

.411 


Metals. 

Sp. Grav. 

Weight 
per cu. 
in. lbs. 

Manganese. 

8 01 

.200 

Magnesium. 

1.74 

.062 

Mercury. 

13-59 

.491 

Nickel. 

8-7 

.314 

Palladium. 

11.4 

.411 

Platinum, rolled.. 

22.07 

.798 

Platinum, cast. 

20.33 

•735 

Silver. 

105 

.380 

Sodium. 

•97 

•035 

Steel. 

782 

.283 

Tin . 

7.29 

.263 

Zinc. 

6.86 

.248 

























































































594 


METALLURGY OF CAST IRON. 


TABLE I37. — ULTIMATE RESISTANCE TO TENSION IN POUNDS PER 

SQUARE INCH. 

Metals. Average. 

Brass—cast.17,000 

wire.48,000 

Copper—cast .19,000 

sheet.32,000 

wire.61,000 

Iron—cast. 10,000 to 40,000 

wrought. 48,000 to 54,000 

wire.70,000 to 90,000 

Lead—cast. 1,200 

sheet. 3,000 

Platinum—wire ... .53,000 

Steel.60,000 to 120,000 

Tin—cast. 5,000 

Zinc. 7,000 to 8,000 

TABLE 138.—TIMBER (SEASONED). 

Wood. 

Average. 

Ash..16,000 

Beech. 12,000 to 18,000 

Hickory.11,000 

Oak—American.11,000 to 18,000 

Pine— “ white and red.10,000 

Poplar. 7,000 

139.—TABLE OF DECIMAL EQUIVALENTS OF 8THS, l6THS, 32DS, AND 

64THS OF AN INCH. 


8 ths. 

32ds. 

64ths. 

31-64 = 

•484375 

1-8 = .125 

I-32 = 

.03125 

I-64 = 

.015625 

33-64 = 

•515625 

1-4 = .250 

3-32 = 

•09375 

3-64 = 

■040875 

35-64 = 

•546875 

3-8 = -375 

5-32 = 

.15625 

5-64 = 

.078125 

37-64 = 

•578125 

1-2 = . 500 

7-32 = 

.21875 

7-64 = 

•IO9375 

39-64 = 

•609375 

5-8 = .625 

9 32 = 

.28125 

9-64 = 

. 140625 

41-64 = 

. 64062 5 

3-4 = -750 

11-32 = 

•34375 

II-64 = 

•171875 

43-64 = 

•671875 

7-8 = .875 

13-32 = 

.40625 

13-64 = 

.203125 

45-64 = 

.703125 

i6ths. 

15-32 = 

.46875 

15-64 = 

•234375 

47-64 = 

•734375 

17-32 = 

•53125 

17-64 = 

.265625 

49-64 = 

•765625 

I-16 = .0625 

19-32 = 

•59375 

19-64 = 

.296875 

51-64 = 

.796875 

3-16 — .1875 

21-32 = 

•65625 

21-64 = 

.328125 

53-64 = 

.828125 

5-16 = .3125 

23-32 = 

.71825 

23-64 = 

•359375 

55-64 = 

•859375 

7-16 = .4375 

25-32 = 

•79125 

25-64 = 

.390625 

57-64 = 

.890625 

9-16 = .5625 

27-32 = 

•84375 

27-64 = 

.421875 

59-64 = 

.921875 

I I 16 = .6875 

29-32 = 

.90625 

29-64 = 

•453125 

61-64 = 

•953125 

13-16 = .8125 
15-16 = .9375 

31-32 = 

.96875 

4 


63-64 = 

.984375 




































INDEX 


PAGE 

Acid proof castings. 291 

Air— 

Mixtures of gases in, and weight of. 71 

Measuring heat by expansion and contraction of. 76 

Humidity of, in cold and warm weather.78, 306, 308 

Cubic feet required to melt 2,000 pounds of iron.* 307 

Air Furnaces— 

Advantages of, in obtaining strong castings.254, 266, 273, 298 
Making changes in the character of iron while melting.. 

HI .259, 343-344 371 

Evils of an oxidizing flame in. 266, 290 

Class of iron generally melted in.267, 273 

Chemical changes in iron by remelting in.290, 305 

Loss of iron by oxidation in.290, 305 

Aluminum — 

The author’s first experience with. 357 

As alloyed with copper. 358 

Manufacture of pure, and its advantages. 358 

How used and its effects in cast iron, etc.358-360 

Specific gravity and melting point of. 360 

Blast— 

Various temperatures, weight and composition of. 70 

Creation of carbonic oxide and acid gases by. 71 

Blast Hot— 

* 

Regulating furnaces by varying the temperature of. .75, 77 
Appliances used for measuring degrees of heat in.... 76 
Advantages and operation of brick stoves for making. .79, 88 

Workings of iron stoves in making. 83 

Action of gases in creating..... 84 






















596 INDEX. 

Blast Furnace Construction— page. 

Depth of foundations . 34 

Form and position of hearth. 35 

Different lines used in. 36 

Character and position of tuyeres. 37 

Different characters of coolers used and their position 38 

Amount of fire brick and clay required to line up. 40 

Character of bricks used and time required to line. .41, 44 

Necessity of expansion space back of the lining. 41 

Methods for drying and life of linings.42, 43 

Factors of greatest protection to lining. 43 

Designs of bells and hoppers and their use.49, 50 

Designs of appliances and methods to prevent explo¬ 
sions .57> 85 

Advantages of increased height. 73 

Blast Furnace Operation- 

Weight of stock charged to fill a furnace.36, 46 

Methods for keeping tuyeres open . 37 

Length of time furnaces run steadily. 40 

Methods of charging.46, 47 

Actions of descending stock.50, 51, 52 

Effects of improper reduction of ores. 53 

Factors causing scaffolding and slips.55, 58 

Relieving gas pressure and preventing explosions. 57 

Limits of fast driving. 76 

Conditions causing cold and hot working. 77 

Regulating temperatures of blast. 77 

Weight of water driven into a furnace by blast. 78 

Methods for hand-tapping and stopping-up. .. .89, 90, 94-96 

The weight of liquid iron in bottom of furnace. 91 

Causes for chilling in furnaces and evils of lime sets.. 92 

Methods for burning out chilled bodies of iron. 93 

Blow Holes in Castings— 

High sulphur in iron causing. 211 

Manganese assisting to prevent.213 

Oxides and occulated gases causing.213, 409 

Phosphorus assisting to prevent...217 































INDEX. 


597 


Blow Holes in Castings— Continued. page. 

Pure iron causing... 219 

Factors causing blow holes on the exterior and interior 

of castings .296, 408, 409 

The part of castings blow holes are found in and their 
difference from shrink holes.408, 409 

Brazing Cast Iron— 

A method for and details of. 585-586 

Carbon— 

Loss of, in making coke. 9, 19 

Amount of fixed carbon in coke. 19 

Desirability of high carbon in fuel. 20 

Making fire bricks of. 44 

Variation of, in pig iron. 131 

Uniformity of, in like grades of pig iron.131, 153 

Diffusion and the state of, in pig iron and castings.. 137, 138 

The amount iron will absorb. 205 

Chromium’s great affinity for.205 

The state of, in grey and white irons.206, 268, 269 

State of, in molten iron.206, 420 

Rate of cooling affecting the state of, combined or 


graphitic .206, 221, 264, 268, 420, 422 

Determining the amount of, in pig iron or castings.... 207 

Effects of variations of total carbon on iron. 246 

Dirty castings caused by high.. 246 

Low silicon iron containing the highest.247, 280 

Impracticability of regulating mixtures by carbon.247 

Its influence to increase heat in molten iron. 247 

Percentages best to insure fluid metal and clean castings 248 

Silicon required according to variation in.248, 280, 282 

Division of carbon into hardening, carbide and tem¬ 
per-carbon .261, 266, 267 

The difference in the state of carbon in gray and chilled 

parts of car wheels.268, 269 

Mixing steel with iron to lower the. 290 

Increase and decrease by remelting iron.304 

Increase of carbon about 1% by five remelts. 340 




























INDEX. 


598 

Carbon Combined— page. 

Variations in the sand, ramming and venting affecting 

the ... 137 , 138, 454 , 485 

Its appearance in fractures ... 206 

Where the lowest is found. 206 

Variations of. being more effective than graphite in alter¬ 
ing the grade of iron. 207 

The importance of understanding the effects other ele¬ 
ments have in forming. 262 

Determining its utility in electrical work castings.284 

Power of sulphur and manganese to promote.285, 420 

The thickness of a casting and the time taken to solidify 

and cool regulating the...286, 420, 422, 453 

Tests proving that the higher the combined carbon, the 
lower the melting point of metals.354, 355 


Carbon, Graphitic— 

Removal from fracture and grain of iron by brushing. ... 117 

Methods of moulding, altering percentage of. 137 

Rate of cooling castings affecting the creation 

of . 167, 221, 286, 420-422 

Its effects in decreasing the contraction of iron. 395 

Its appearance in fractures. 206 

Enlarging the grain of iron.420-421 

Principles involved in the formation of.420, 421 

Carbonic Oxide and Acid Gases— 

Heat units contained in and creation of. 71 

Explosive nature of oxide gas. 86 


Castings—Gray and General— 

Best composition to resist fusion or high temperatures.. 230 

Different kinds made, showing forty specialties.252 

Character of those having steel scrap mixed in. .265, 267, 275 
Description of the color, grain, etc., of different grades 

of iron used in.461-469, 558-569 

The A. F. A. specification for test bars and gray iron.580-583 





















INDEX. 


599 


Castings, Chilled — PAGE. 

The different kinds used.254, 263 

Lines of crystallization in.259, 434 

Necessity of tests in making. 259 

Difference between the wear of heat and friction upon.259, 264 

Difference in the hardness of.259, 260, 444 

Peculiar effect of sulphur and manganese upon the hard¬ 
ness of .259, 260, 271 

Factors affecting and preventing “cola shuts” and “chill 

cracks” in .260, 262, 415 

Interlacing of the gray body with a chill of.261, 264 

General composition of. 262 

Temperature of molten metal partly regulating the depth 

of chill in .262, 373, 433 

Mixtures for rolls, and points to be considered in mak¬ 
ing .263, 266 

Thickness of chill used in rolls. 263 

Sharply defined chill in joining gray body of. 264 

Difference required in the chill of rolls used for cold and 

hot rolling . 264 

Analyses of roll mixtures.205, 266, 267, 299, 570 

Analyses of car wheels showing difference between the 

chilled and gray parts.268, 269, 270 

Thicknesses of chill used in car wheels.271, 446 

Annealing car wheels. 448 


Castings, Malleable— 

Principles of annealing.288, 289, 290 

The depth decarbonizing affects. 289 

Contraction and expansion of, and percentage of sili¬ 
con in . 289 

Castings, White Iron— 

Factors to be considered in making. 287 

Difference in the strength of. 287 

Percentage of silicon to make castings ranging from 

one-half inch to four inches thick.. 288 

Necessity of larger gates to pour white than gray iron 
and the difference in their shrinkage and contraction.. 288 
Practicability and process of annealing. 288 


























6oo 


INDEX. 


PAGE. 


Chemical Analyses, the Utility of— 

Conditions exacting complete analyses of irons. ... 132, 197 

Methods of sampling pig iron to make.140, 195, 196 

Opposition to mixing and grading by. 163 

Self-interest retarding past advancement and adop¬ 
tion of .164, 166 

Difficulty of securing uniform.180, 181, 182 

The evils resulting from non-uniformity of.180, 182 

Variation found in analyses of one sample of drillings 

by two investigators to test the utility of.180, 181 

Difficulty of chemists knowing the correctness of. .. .181, 182 

Number of founders using. 194 

The wisdom of founders checking blast furnace analyses 

and the chances for mistakes in.194, 195 

The simplicity of founders mastering the knowledge of 

working by .195, 198 

Difficulty of small founder utilizing analyses, and how 

to best overcome it.196, 197 

The necessity of utilizing.205, 262 

Benefit to founders in making chilled castings. 258 

The necessity of working by, in making chilled castings 262 
Same analyses in different irons, not giving like hard¬ 
ness to like castings. 282 

Chill Tests— 

The character of, and how made. .220, 432, 502, 506, 513, 551 
Effect of different temperatures in varying the depth 

of •••; .262, 373, 433 

As a guide to the tensile strength of semi-steel. 277 

Chill test moulds adapted to blast furnace and foundry 

work .502-508 

Chill tests for round bars cast on end.513, 515 

Chill and fluidity strips used for the A. F. A. series of 

tests . 548 , 55 B 561 

Chrome-Ferro— 

Refractory nature and behavior in a molten state. 218 

Clays— 

Quality required and use of in lining furnaces. 41 

Grades used for manufacturing fire bricks. 44 

Kind used for stopping up furnaces. 98 
























INDEX. 6oi 

Coke— page. 

By-products ovens for making.3, 6 

First successful use of. 3 

Advantages of coal over. 3 

Principles involved in making. 4 

Natural, where found. 6 

Operation of oven for making.6-13 

Braise in . 9 

Moisture in .9, n, 307 

Removal of pyrites and slate from. n 

The yield obtained from ovens. 13 

Density and cell structure of.13, 14 

Physical tests and chemical analyses of.15, 18 

Difference in forty-eight and seventy-two hour. 16 

Twenty-four, ninety-six, and 124-hour coke. 17 

Gas house coke and its utility. 17 

Sulphur and phosphorus in.18, 21, 22 

Different makes of. 18 

Black ends and black butts in. 18 

Qualities in good and poor. 18 

Localities conceded to produce the best.18, 23 

Stock coke, how created and its utility. 19 

Percentage of fixed carbon in. 19 

Ash, its composition and percentages in. 20 

Chemical properties desirable in. 20 

Evils of scarcity of good water in making. 22 

A quick test for sulphur in. 22 

Weight of soft and hard coke per bushel. 23 

Different amounts of hard and soft coke required to melt 23 
Conditions under which greatest heat is obtained from.. 75 
Amount of coke theoretically required to melt iron.307 

Compression Tests of Iron— 

The transverse, deflection and chill of an iron a good 

index to . 439 

As obtained in different grades of iron by the A. 

F. A.558, 560, 562 
































6o2 


INDEX. 


Contraction of Iron— page. 

Sulphur causing excessive shrinkage and. 212 

Diagram showing the effect of expansion and after con¬ 
traction of different grades.. .389-300 

Confined expansion giving rise to greater contraction. .. . 389 
Light bodies contracting more than heavy, causing in¬ 
ternal strains in castings .390, 419, 421, 440 

The relation that shrinkage maintains to. 414 

Difference in contraction between light bars, cast in a 

sand and a chill mould. 414 

Comments on contraction, showing why founders mak¬ 
ing chilled castings have difficulty with.. 415 

Impracticability of set or standard rules for.418, 422 

Cases where castings are larger than their pattern. 419 

Difference in the contraction of light and heavy castings 420 

Principles involved in creating.420, 421 

Evils of internal contraction strains. 440 

Amount allowed in car wheels for. 444 

Designing car wheels to best withstand. 446 

Variations in the dampness of sand and pouring tempera¬ 
tures affecting the strength and contraction of small 

and large bodies.454-457, 484, 511 

Excessive contraction causing castings to crack and fly to 
pieces . 466 

Crucibles— 

Objections to use of for melting iron 

As used in melting iron. 

Care necessary in preserving.. 

Cupola Construction and practice— 


Plans for stopping up. 98 

Methods for banking. 126-129 

Plans for conveying iron to and mixing ready for charg¬ 
ing in . 198 

One system for recording the chemical and physical 

properties of mixtures melted in. 199 

Plans for constructing small.241, 364, 501 

As used for testing different pig irons.259, 262, 267 


363, 459 

•... 365 
•... 367 

























INDEX. 


Cupola Construction and Practice— Continued . page. 

As used for making strong castings.277-279 

Reasons for different strengths of iron being obtained 

from the same mixture in same heat. 306 

As prepared for testing oxidation of iron. 310 

Loss of iron by oxidation.310, 318 

As arranged for testing the comparative fusibility of 

metals . 325 

Methods for preparing and charging small. 

. 325 - 327 , 364, 499 , 500 

Combination small crucible furnace and cupola. 364 

Utility of small for blast furnaces. 495 

Cost of a small cupola for testing purposes. 496 

Pressure of blast in small. 499 

Direct fletal— 

Evils of kish in.117-118 

Its utility, and methods for handling.,117, 119 

The life and fluidity of. 118 

Best grades to use.118, 120 

Character of castings best made of.118, 120 

Drop Test for Castings— 

As used for testing car wheels.446-448 

Etching Steel and Cast Iron— 

Details for and prints of.587, 588 

Expansion of Iron- 

Annealing white and malleable causing. 289 

At moment of solidification, demonstration of.. .386, 387, 427 
Causing shrinkage and the necessity of feeding to make 

solid castings .387, 39 2 

Hard grades expanding more than soft.387, 389, 394 

Diagrams displaying expansion and contractions of dif¬ 
ferent irons .389, 39 ° 

Retarding expansion giving rise to greater contraction. . 389 

Expansion unaffected bv temperature of molten metal.. 391 

Period of expansion varying with the size of casting. 392 

























604 


INDEX. 


Expansion of Iron— Continued. page. 

Confined expansion decreasing shrinkage and contraction 394 
Views of appliances used to test expansion and contrac¬ 
tion .398-402, 424 

The practicability of utilizing expansion tests of iron to 


define its grade. 427 

Permanent expansion due to reheating iron. 431 

Fire Bricks— 

Composition of and different kinds used. 44 

Composition which stands heat and friction best. 44 

Fluxes and Their Use- 

Amount required in fluxing furnaces...46, 53 

The object of fluxing. 59 

Elements essential in and the different kinds used. 59 

Effects of silica in. 60 

Physical character of some grades of. 61 

Object of roasting. 62 

Chemical character of. 63 


Variation in the grain of pig iron by variation in use of.. 64 

Formulas— 

Best adapted for computing comparative strength of 


standard test bars.474-477 

Lack and need of perfect formulas.476, 477, 530 

Fuels— 

Charcoal as used in making iron. 161 

Charcoal, its freedom from sulphur. 162 


Fusibility of Iron, Comparative Tests of— 

Effects of adding phosphorus to molten iron as defined 

by immersion test.230, 232 

Comparative fusing tests of small sand and chilled roll 

castings .312, 332, 335 

Immersion tests of small sand and chill rolls.314, 415 

Importance of knowing comparative fusibility of differ¬ 
ent irons . 323 

Conditions necessary to test the.324 























INDEX. 605 

Fusibility of Iron, Etc.— Continued. page. 

Comparative fusing tests of hard and soft irons in a 

cupola .328-330 

Comparative fusing tests of hard and soft iron in an 

open-hearth furnace .331-332 

Comparative fusing tests proving that the chilled remelt 
is softer than the grey of the same chilled casting. .337-339 

Comparative fusing tests of cast iron and steel.342-344 

Comparative fusing tests and melting points of iron, 
chromium, tungsten and manganese (72 samples) in an 

essaying furnace .350-353 

Comments on fusibility and melting points of metals. .. . 355 

Hardness Tests— 

Impracticability of, for testing the grade of pig iron. .175, 176 


Methods used for testing hardness.234-238, 434-438 

Past unsatisfactory nature of. 434 


Heat— 

Units of, in carbonic oxide and acid gases. 71 

Production, absorption and loss of, in furnaces. 72 

Appliances for measuring. 76 

Influence of carbon in iron, to increase. 247 

Radiation of, in test bars.484. 485. 487 


Illustrations* 

Plan of Bee, hive coke ovens. 8 

Coking in mounds. 10 

Drawing coke from ovens. 12 

Loading coke for shipment. 21 

Buchanan separator for dephosphorizing ores. 28 

Elevation view of blast furnace. 35 

Views of modern blast furnace.4$, 47, 48 

Action of stock descending a furnace. 49 

Operation of furnace bell and hopper. 50 

Mr. P. C. Reed’s gas escaping device. 57 

Massick & Crooke’s brick hot blast stove. 80 

Iron hot blast stoves.81, 83. 84 


♦This work contains 153 illustrations. 


























INDEX. 


606 

Illustrations— Continued. pagb. 

Illustrations of tapping and stopping furnaces. 90 

Burning out chilled furnaces. 93 

Stopping tools . 94 

Tapping and stopping up cupolas. 98 

Molding, casting pig iron and open sand \vork..ioi, 103, 104 

Views of sand and chilled cast pig iron. 116 

Samples showing deceptive appearance of pig 

fracture.167, 168, 170, 173 

Hardness tests of pig iron. 177 

Method of moulding and pouring a standardized drill¬ 
ing casting . 185 

View of sample case of standardized drillings. 189 

Methods for sampling pig iron. 195 

Appliances for handling phosphorus. 229 

Testing the fusibility of metals by immersion.. .232, 416, 417 

Device for testing contraction of test bars. 237 

Drill press arranged to test hardness of metals. 239 

Methods for measuring hardness.239, 240 

Twin shaft cupola ... 241 

Section of chilled cast car wheel. 264 

Chill mould and casting of small roll. 312 

View of the fracture in a gray and chilled roll. .333, 337, 338 
Chatelier Pyrometer arranged to measure the melting 

point of iron, etc...346, 347, 348, 354 

Combined cupola and crucible furnace. 364 

Fracture of chills poured with hot and dull iron.373 

Plan for casting fluidity strips flat.: .. .. 375 

Device for measuring expansion of ]/ 2 -inch sq. bars.384 

Diagrams of automatic expansion records.389, 390 

Apparatus for recording expansion and contraction of 

metals .398, 400, 401, 402 

Typical position of shrink holes.405, 406. 407 

Castings showing internal and external blow holes.408 

Shrinkage test pattern and casting. 409 

View of pouring shrinkage tests. 410 

Contraction chill and sand test mould. 411 


Apparatus for recording stretching qualities of iron.... 424 































INDEX. 


607 


III us trations —Contin ued. 

Sketch of patterns for testing stretching. 425 

Prof. Turner’s machine for testing hardness. 436 

Method for thermal test of car wheels. 444 

Drop testing machines for car wheels.447 

Thirty views of the fracture of test specimens.472, 473 

Beam of testing machine and testing bars transversely. . 482 

Views of radiation of heat in round and square bars. 484 

Difference of uniformity in grain of round and square 

bars . 486 

Difference in grain of the cope and nowel side of flat 

poured bars .409-491 

Small cupola for testing purposes, etc. 501 

Flask and pattern for ramming flat test bars cast on 

end .503, 507, 509 

View of chill moulds for making chilled tests. 506 

Patterns and flasks for round bars with fluidity strips 
moulded flat and cast on end. .514. 515, 516, 522, 524, 527 
Moulding and casting plain round bars on end....527, 578 
A set of 198 test bars of Bessemer iron for A. F. A. .. . 541 
Patterns and boxes for the A. F. A. tests.543, 544, 546, 548 
Malleable flasks for moulding A. F. A. green sand bars. . 549 
Moulds in place for casting a set of A. F. A. bars.... 550 
Plan and elevation sketch of A. F. A. test bar moulds.. 552 

Plan of runners, pouring A. F. A. bars. 554 

View of casting a set of A. F. A. bars. 556 

Device for imprinting contraction tips. 557 

Fracture views of chilled test pieces obtained by A. 

F. A.559, 56i, 563 

Transverse and tensile test bars recommended as stand¬ 
ards by A. F. A..582, 583 


Impact or Shock Tests of Iron— 

Instances of their impracticability. 439 

A practical way to apply. 44 ° 

As conducted in tumbling castings proving beneficial. ... 441 
Desirability of gradually increasing the severity of shock 
tests in castings required to stand sudden shocks, etc. . 442 






















6 o8 


INDEX. 


Iron— pa ge. 

Refining and the character of pure.162, 218 

The metallic and non-metallic elements of.202 

Composition of atoms and molecules and number of ele¬ 
ments in .202-203 

The general acceptance of the terms metal and metalloid 

to define elements in.202-203 

Method of distinguishing metallic from non-metallic ele¬ 
ments in . 203 

Constituents of . 218 

Definition of tenacity, elasticity, toughness, strength, brit¬ 
tleness and chill of. 220 

The evils of excessive impurities in .249, 250 

Elements that constitute impurities in. 249 

Character of iron which shows the least impurities.... 250' 

The brand of, most free of impurities. 250 

A method of determining the metallic iron in.251 

Iron Mixtures and Analyses— 

Utilizing Bessemer iron in making ingot moulds and 

other castings .157, 253, 537, 558 

Using ferro-silicon in emergency cases to make.211 

For stove plate and light machinery castings. 

. 253, 281-283, 299, 465, 537, 562, 566, 568 

For medium weight gray iron castings. .. .253, 280, 299, 464 

For heavy gray iron castings. 

. 253, 273-280, 299, 463, 537, 564, 570 


Of stove plate, burnt grate bars, annealing pots and tin 

sheet scrap .253, 296, 299, 466, 565 

For cannons, guns, etc.253, 274, 275, 278, 279, 299, 460, 537 569 

For car wheels .253, 267-271, 299, 462, 537, 566, 570 

For chilled rolls.254, 265, 266, 267, 299, 461, 536, 537, 564, 570 

Methods for calculating the analyses , of.255-257 

Greater difficulty of making mixtures for chill than gray 

castings . 258 

Factors to be considered in making chilled rolls. 

. 259-261,263-265 

General composition for chilled castings. 262 

Character of pig iron and scrap used for chilled rolls. .. . 265 


























INDEX. 


609 

Iron rtixtures and Analyses— Continued. page. 

Steel employed in and how used. 

. 2(5 5 , 271, 273, 276, 342 - 344 , 568 

Analyses of chilled rolls.265, 266, 267, 299 

Difference in mixtures for chilled rolls and car wheels.. 267 

Analyses of car wheels .268, 269, 270, 299 

Analyses of the gray and chilled bodies of car wheels 

.268, 269 

For sand rolls.273, 564, 570 

Analyses of some specially strong gray. 

. 274, 275, 276, 278, 299 

Approximate analyses of coke iron mixtures for castings 

ranging from y 2 " to 4" thick. 280 

For dynamo castings and those used to transmit electric 

currents . 284 

Analyses of gun iron, chill rolls, car wheels, light and 
heavy machinery, stove plate and white iron, etc.... 

. 299, 537, 570 

Three methods for melting small samples to test. 362 

Non-scient»fic practice of mixing irons prior to 1890.... 497 


Iron Ores— 

Oxides and impurities in. 25 

Definition of lean and rich. 25 

Percentages of iron and silica contained in commercial 

ores . 26 

The function of silica in. 26 

Percentage of manganese in. 27 

High and low phosphorus in. 27 

Methods for dephosphorizing magnetic. 28 

Classification of hematites, magnetites and carbonates.. 29 

Characteristics of brown hematites, carbonates and spathic 30 


Titaniferous ores and manufacture of ferro-titanium.31, 218 


Mill cinder in mixture with... 32 

Effects of varying temperatures in reducing.52-53, 71 

De-oxidation of.52, 7 2 

Reduction of non-metallic matter in. 52 

Scaffolding furnaces by expansion of.56, 77 

Different composition of, from same mine. 131 



























6 io 


INDEX. 


Kish— 


PAGE. 


Its production and appearance at blast furnaces. ... 117, 369 


Evils of in metal.117-118, 248 

Difficulty of eliminating from metal. 118 

Grades of iron most free of.120, 248 

Created in remelted iron by high carbon. 248 


Limestone— 

Affinity for sulphur.53, 60 

Chemical and physical character of. 61 

Roasting of . 62 


rianganese— 

Percentages in ore and manufacture of ferro-. 27 

Uniformity of, in like grades of iron.136, 151, 153 

Percentages in different brands of pig iron. .. . 145-147, 213 

Influence of, in causing iron to absorb carbon. 205 

Its influence to harden iron without closing grain or 

changing soft appearance in fractures. 205 , 213, 286 

Its peculiar effect or. hardness and chill compared with 

that of sulphur .211, 260, 271 

Its general tendency to strengthen iron.212, 244, 245 

Percentages in pig iron and amounts permissible in cast¬ 
ings .213, 282 

Its power to neutralize the effects of sulphur.. .213, 260 

Increasing the life and fluidity of molten metal.213, 262 

Beneficial as a flux to expel oxides or occulated gases in 

metal . 213, 297 

Loss of, by remelting iron-214, 257, 271, 295, 300, 315, 341 

Methods for adding it to molten metal.214, 241 

Its power to soften a low grade of iron when added to 

molten metal .214, 243, 244 

Results of experiments in adding manganese to molten 

iron . 241, 243 

Its peculiar effects in driving graphite to the surface of 

castings . 244 

Evils of mixing with dull iron.244 

Strengthening white iron by the addition of. 245 

Essential in car wheels to assist them in standing ther¬ 
mal tests . 271 

Percentage admissible in light castings. 282 



























INDEX. 


6l I 


PAGE. 


Plelting Iron— 

In small cupolas to make experiments or test mix- 

tlires ;.238. 325, 364, 495. 499-502 

In a crucible, and how to operate it.363, 367 

riolten Iron— 

Composition of a flux to purify. 276 

Exposition of some fluxes used in. 277 

Judging the grade of iron, when solid, by the appear¬ 
ance of . 369 

Actions and appearance of different grades in.369-371 

The utility of thin tapering strips on test bars to test the 

fluidity of .502, 515-517 

Best temperature for pouring test bars. 526 

Oxidation of Iron. Loss by rieltmg, Etc.— 

Methods of preparing cupolas to test.310 

Difference of sand coated and chilled iron.311, 318 

Comparative tests of iron on low and high beds of fuel. . 

. 313 , 315 

Comparative tests of stove plate and heavy iron.314. 317, 318 
Summary notes on. 322 

Phosphorus— 

The utility of fuels containing low and high. 22 

Advantage of low phosphorus in ores for certain irons.. 27 

Methods of dephosphorizing ores. 28 

The most effective element in increasing life and fluidity 

of molten metal .28, 216, 226, 282, 285 

As found in mill cinder. 32 

Uniformity in like grades of iron.136, 151, 153 

Percentages in different brands of pig iron. 145-147 

Percentages beneficial to toughness in castings. . 158, 216, 274 

As found in Bessemer and Foundry irons. 215 

High phosphorus causing brittle and hard castings.... 

. 216, 282, 285 

How it is obtained in iron. 216 

Its effect in neutralizing the evils of sulphur. 217 

Effects of adding to molten iron. 226 

Strengthening castings by adding it to molten metal.... 227 

























6l2 


INDEX. 


Phosphorus— Continued. page. 

Its influence to flux and drive off impurities. 227 

Methods for adding phosphorus to molten metal... .228-230 
Percentages best adapted to increase fusibility of iron.. 230 
Testing the fusibility of phosphorus iron mixtures. .231-232 


Increased by remelting iron.257, 304, 341 

Effects of, upon chilled iron. 261 

Percentage used in light castings. 282 

Pig Iron- 

Percentages of impurities in. 26 

Manufacture of mill cinder mixed.31-33 

Carbonizing in furnace. 5 2 

High sulphur and silicon in the same grade of. 54 

Methods for moulding and pouring.99-111 

Causes for boils in making.100, 105 

Character of sand required in making.100, 105 

Cause of jump cores in making. 102 

Breaking and removing pig iron from casting house.... 106 

Designs for patterns for moulding. no 

Principles involved in casting chilled or sandless. 113 

Parties manufacturing machines for casting chilled. 113 

The economy and advantages obtained by using chilled.. 114 

Recommendations for chilled. 115 

Difference in the form of sand and chilled. 116 

Difficulty in controlling silicon and sulphur percentages 

in making .130, 137 

Changeable and constant metalloids in making. 132 

The grade giving the least difficulty in making. 132 

Segregation of metalloids in making. 134*137 

Analysis of gray spots in. 134 

Desirability of using hot melted. 137 

Evils of dull melted. 138 

Mixing effects obtained by remelting.138 

Necessity of mixing blast furnace casts of.139-143 

Plans of mixing at furnace and foundry for charging. 140-142 

Method of sampling to make analyses of.140, 195-196 

Advantage of casting chilled pig from ladles. 142 

Objectionable methods of analyzing.142, 143 































INDEX. 


613 


Pig Iron— Continued. 


PAGE. 


Evils of using ill-mixed casts of.139-143 

Best method of grading.144-145 

Definition of “brand” and “grade” of.144, 396 

Difference between Foundry, Charcoal, Bessemer, Gray 
Forge, Basic, Ferro-Silicon, Ferro-Manganese, Mottled 

and White .145-147 

Number of founders in 1901 grading by analyses. 148 

Deceptive appearance of the fracture of.. 148,169,173,177, 178 
Suggested systems for standardizing grading by analy¬ 
ses .148-153 

Erratic and objectionable systems of grading by analy¬ 
ses practiced up to 1902. 149 

Percentage of silicon required to change the grade of. 150, 155 
Desirability of occasional analyses of all metalloids when 

purchasing Ferro-Silicon .152, 154, 197 

Conditions requiring analyses of all five metalloids. 153 

Suggestions to furnacemen for advertising. 154 

Impracticability of exacting certain percentages of 

graphite or combined carbon in purchasing. 154 

Methods for utilizing different grades to make a mix¬ 
ture . 155 

The value of standardized drillings in analyzing. 

. 156, 181, 192 

Process of refining . 162 

Excuses to account for ill results through being guided 

by the fracture of.164. 165, 170 

Tests demonstrating the deceptive appearance of frac¬ 


tures in .172, 174 

Impracticability of hardness tests for judging the grade 

of . 175-176 

Two ways of producing hardness in. 175 

The percentage of furnace casts that will be deceptive 

in fractures of .176-179 

Necessity of utilizing analyses and physical tests and 
what they define in making mixtures of. .194, 205, 258, 497 
Evil practice of foundrymen relying upon furnacemen 
to tell them what they should use 


197 























INDEX. 


614 


Pig Iron— Continued. page. 

A good plan for beginners to follow in first purch's- 

ing .200, 283 

The fallacy of considering the grain of pig metal in con¬ 
nection with chemical analyses. 200 

The gross weight of sand and chilled cast .300. 589, 590 

The fallacy of claiming bad iron for ill results. 497 

Pig Iron, Bessemer— 

Utility of, for certain kinds of castings and mixtures 

of .146, 157 

The restrictions which define..146, 159, 215 

Impracticability of defining it from Foundry iron by 

fracture .157, 160 


Pig Iron, Charcoal— 

Highest silicon in...146, 245 

Being replaced by coke and anthracite iron.160, 267, 279 

Pronounced character of its fracture. How defined from 

other irons . 16^-261 

The element causing strength in castings made of. 161 

Deterioration of by melting in cupolas. 162 

Peculiarity and its advantage over coke and anthracite 

pig iron often due to low sulphur.211, 212, 261 

The softest strong casting made of. 212 

Difference in and advantage of cold and hot blast..265, 274 
Some special brands of strong.274, 275, 278. 279 

Pig Iron, Gray Forge and Basic- 

Limitation of elements in. 146 

Utility of and appearance of fracture., 146 

Pig Iron, Hottled and White- 

Conditions of furnace making, and analyses of. r<\ 7 

White iron strengthened by the addition of manganese.. 245 
Annealing white iron castings. 288 

Pig Iron, Ferro=Manganese— 

Spiegeleisen or Spiegel, its power to absorb carbon...27, 205 

Analyses of and standards for.27, 241 

Utility of .27, 214. 241, 297 























INDEX. 


61 5 

Pig Iron, Ferro=SHicon— page. 

Kind of fuel and ores used to make.26, 147 

Erratic composition of. 152 

Utility of .210, 211, 293 

Using ferro-silicon in emergency cases to make mix¬ 
tures ... 211 


Pyrometers— 

Designs of ...76, 344 

Methods for using.76, 345-349 


Sands— 

Adaptability of coarse grades for moulding pig iron. 100, 112 
Variations in the “temper” of, affecting the carbons, con¬ 
traction and strength of iron.451, 453-457, 484 

The “temper” of sands best for moulding test bars. .523, 580 

Scrap, Iron- 

Castings requiring only..*.-253, 272, 296 

Methods of grading chilled.265, 294 

- Percentage of shop scrap made in light and heavy work 

foundries . 281 

Difficulty of analyzing miscellaneous. 292 

Imaginary basis to define chemical properties of. 292 

The evils of using burnt.295-297 

Approximation of analyses in and rules for grading. .. . 295 

Injurious effects of rusty and methods for fluxing.296 

Chilled bodies of the same casting giving a softer re¬ 
melt than gray .337-339 


Scrap, Steel and Wrought— 

Using steel in iron mixtures.265, 271, 275, 276, 344 

Using wrought in iron mixtures.271-272 

Comparative fusibility of .342, 355 

Increase of carbon in by remelting.343, 355 

Semi=Steel— 

First introduction of. 276 


Refutation of some claims made for high strength. ..277, 343 






















6 i6 


INDEX. 


Shrinkage vs. Contraction— page. 

Difference in their action. 386 

Elements affecting their application in foundry 394-395 . 411-415 

Shrinkage of Iron—* 

Principles involved in causing.387, 392 

The constant relation existing between expansion and... 387 
Not increased by hot poured metal, as generally thought 391 
The factors causing hard iron to possess greater shrink¬ 
age than soft iron.391, 394, 395 

That period of solidification which exacts the greatest 

attention and feeding to supply the. 393 

Metal poured into iron moulds showing less shrinkage 

than into sand. 394 

The part in which shrinkage will occur, if any exists.404, 485 
The necessity for engineers, designers and draftsmen to 

understand the principles of. 404 

Illustration of castings showing typical position of shrink 

holes .405, 406, 407 

Tests to ascertain the percentage of shrinkage occurring 

in hard and soft grades of iron.409-413 

The amount gray and chilled iron shrinks per 100 
pounds .411-413 

Silica- 

Effects of temperatures on, and its refractory nature.26, 60 
Percentage in ores and fuel and amount absorbed in 

making iron . 26 

Amount taken up by iron and carried off in slag.26, 66 

Silicon- 


How obtained in iron.26, 53-54 

Temperatures in furnace regulating percentage of, in 

lron . ;••• .26, 53-54 

Diffusion of, in pig iron and castings. 134 

Impracticability of using physical tests to determine. .144, 396 


Percentage of, in different brands of iron.145-147, 21c 

High temperatures and silicious ores required to make 
high .. 161 

"Effects of changes in total carbon on 246 . 



















INDEX. 617 

Silicon— Continued. page. 

Percentage required to change the grade of an iron. .150, 155 
The influence of, to retard iron absorbing carbon. .205, 208 
Its utility to soften, regulate and cheapen mixtures. .207-211 

The first to advance the utility of.207, 208 

Its power to increase the fluidity and life of molten metal 208 
Used as a base for changing the grade of mixtures. .208, 296 

Care necessary in using and its evil effects.208, 209 

Percentage used in light castings.209-211, 281 

Ways in which silicon hardens iron.208, 209, 281, 437 

The highest percentage permissible in soft castings 

.209, 281, 283 

Causing brittle castings.209, 222, 283 

Example of extremely low silicon in light castings. 209 

The amount that can be absorbed by iron. 210 

The percentage in pig most desirable to use for regulat¬ 
ing mixtures . 210 

The amount of scrap that four per cent silicon pig may 

carry .211, 279 

Its peculiar appearance in fracture. 211 

Amount required when total carbon changes in order to 

keep a uniform hardness.246, 280, 282 

Loss of by remelting.257, 303, 315, 341 

Low, showing a greater chill on edges of light castings 

than excessive use of. 283 

Slags— 

Creation of ... 52 - 53 , 63, 66 

Amount of iron in furnace. 53 

Defining the grade of iron by color and condition of.. 63 

Action of basic and acid elements in. 63 

Chemical relation of iron to . 65 

Percentage of silica in. 66 

Weight produced in making iron . 66 

Methods for disposition of. 66 

Manufacture of mineral wool, from. 67 

Slagging Out— 

Percentage of refuse carried off by.. 63 

Plans used by furnaces.66-67 

Loss of iron by, in cupolas.319-322 



























6 i8 


INDEX. 


Specific Gravity — page. 

Difference between gray and white iron. 219 

Remelting iron greatly increasing its. 340 

Of the two ends of vertical poured castings.378-381 

Expansion of iron equalizing. 381 

Test of solid iron floating in molten metal.386 


Stretching Iron — 

Percentage in tensile tests. 220 

Causing castings to be larger than their patterns.422, 428-429 
The utility of in permitting the manufacture of cast¬ 
ings ......422,430 

Description of appliances used for testing. 423 

Period of cooling from a solidified state affecting. .426-429 

Degrees in temperature best affecting.426, 429 

Demonstrations of, in heavy founding.428-429 

Expansion of large cores and their rods causing. 429 

Slow and uniform cooling assisting stretching and sav¬ 
ing castings from cracking. 430 

Standardized Drillings— 

Origin and inception of plan to establish a central 

agency to distribute standardized drillings.182, 183 

Method of moulding and pouring casting for making 

standardized drillings for testing.184, 186 

Method of turning and mixing turnings to obtain 

standardized drillings .186, 188 

Designation of samples and price.187-188 

The labor attending the introduction of standards'. . 188, 190 
Names of some firms using standardized drillings. . 190, 191 
Testimonials, in praise of excellence and utility of.. 192, 193 


Sulphur— 

Whether exposure of coke to weather reduces. 11 

Percentage of, which coke contains.21-22 

Scarcity of good water in making coke increasing. 22 

Evils of fuels containing high.22, 225 

An approximate quick test for sulphur in fuel. 22 


Percentage of, in pyrites and methods for reducing it 
in ores ... 


28 
























INDEX. 619 

Sulphur— Continued. page. 

Irregularities in the work of furnaces regulating. 53 

Affinity of iron for .53, 225 

How iron obtains .53, 211, 341 

Found greatest in the top face of some pig irons. 134 

Spots in castings. 138 

Percentage in different brands of iron.145-147, 212 

Greatest percentage found in iron.147, 212, 225, 396 

Power of to neutralize the effects of silicon. 

. 150, 208, 212, 285, 303 

Hardening iron and causing blow-holes.211, 213, 225, 39^ 

Softening effects in iron free of carbon, etc. 208 

The power of to increase the fusibility of iron. 211 

Its peculiar effects on hardness and chill of iron. 

. ... 211, 260, 271, 283 

Its effects in making molten metal sluggish and solidify 

rapidly . 211 

Making hot short iron.212. 213 

Excess of, weakening iron. 212 

Causing excessive shrinkage and contraction or holes 

and cracks in castings . 212 

Method for adding sulphur to molten iron.223, 388 . 

Ways in which it strengthens iron. 224 

Maximum amount of sulphur iron may absorb.225, 396 

Percentage of increase by remelting iron. 

. 257, 271, 302-305, 341 

Highest percentage permissible in light castings. 282 

The length of time iron remains in cupola affecting an 

increase of . 341 

The great need of founders fearing the evils of.396 

Tables— 

Yield of coke from coal. 13 

Tests and analyses of 72-hour coke. 15 

Analyses of coke from six different localities. 18 

Anatyses of ash in Connellsville coke. 20 . 

Analyses of mill cinder. 3 2 

Analyses of three different brands of limestone. 61 

Analyses of slags from different ores and iron. 65 



































620 


INDEX. 


Tables —Continued. page. 

Volume and weight of nitrogen and oxygen. 7 1 

Heat production, absorption and loss in a furnace. 7 2 

Segregation of sulphur in pig iron. 134 

Analyses of pigs from the different beds of a change¬ 
able and normal working furnace. 135 

Silicon analyses of the different beds of eight casts.... 136 
Changes in sulphur and silicon to maintain similar * 

hardness . I 5 I 

Grading pig iron from No. 1 to No. 10 with an increase 

of .25 in silicon each number. I5 2 

Analyses of deceptive pig iron samples and thei. cast¬ 
ings . I7 1 

Tests taken from castings made of deceptive pig iron. . 172 
Analyses of three deceptive pig specimens. 174 

Variations of the analyses of two test samples of 
drillings . 181 

A method of keeping records of chemical and physical 

tests . 199 

Analyses distinguishing Foundry and Bessemer iron.... 215 

Test and analyses of sulphur addition to molten iron.. 223 
Tests and analyses of adding phosphorus to molten iron 231 
Comparative fusing tests of phosphorus addition to iron 231 


Tests and analyses of variation of manganese in different 

irons .235, 236 

Percentage of iron and impurities in weak and strong 

castings . 250 

Character of forty specialties made of cast iron.252 

Methods for calculating the silicon and other metalloids 

in making mixtures of iron. 256 

Approximate analyses for chilled roll mixtures. .*.266 

Analyses of two rolls that stood well.267 

Analyses of car wheels that stood thermal tests and 

good wear . 268 

Analyses of car wheels which did and did not stand 

thermal tests .268-269 

Analyses of the graphitic and combined carbon of 
wheels which stood and did not stand thermal tests. . 270 
Mixtures for gun carriages.274, 275 





















INDEX. 


621 


Tables— Continued. 


PAGE. 


Mixture for semi-steel .275-276 

Mixture and tensile strength of high grade Salisbury 

carbonate iron . 278 

Approximate analyses of coke iron mixtures.280 

Changes in the relation of silicon and total carbon to 

maintain like hardness .282 

Analyses of dynamo or electrical work iron mixture. . 284 
Percentage of silicon to give white iron in varying 

thicknesses of castings. 288 

Analyses of seven typical foundry mixtures. 299 

Transverse and tensile tests of seven typical foundry 

mixtures . 300 

Decrease in silicon and increase in sulphur by remelting 

iron . 302 

Comparative oxidation tests of protected and unprotected 

surfaces . 311 

Comparative fusing tests of gray and chilled iron by 

immersion . 312 

Comparative oxidation tests of iron charged on high 

and low beds of fuel. 313 

Comparative oxidation of stove plate and heavy iron. . 314 
Analyses of silicon and manganese each from low and 

high beds . 315 

Analyses of iron in slag from stove plate and heavy iron 316 

Percentage of loss of different irons by oxidation. 318 

Comparative fusing tests of high and low silicon and 

low sulphur iron with analyses.328-329 

Analyses and specific gravity of gray and chilled irons. . 334 

Comparative fusing tests of gray and chilled irons. 335 

Analyses of chilled and gray same iron remelts.336 

Comparative fusing tests of cast iron with open hearth 

steel, with analyses .340-341 

Comparative melting points of cast iron, ferro-manga- 
nese, ferro-silicon, ferro-tungsten and ferro-chrome. . 

. 352-353 

Tests and analyses of hot and dull poured chilled irons.. 376 
Specific gravity of the upper and lower end of vertical 
poured castings, with analyses.-.-378-379, 381 






















622 


INDEX. 


Tables— Continued. 


PAGE. 


Shrinkage and contraction of gray and chilled iron.... 411 
Influence of silicon on the hardness and tenacity of iron. 437 
Analyses of car wheels that did and did not stand ther¬ 


mal and drop tests 


448 


Tests of gun metal, chill roll iron, car wheel iron, heavy 
and light machinery, stove plate, and sash weight iron, 
with summary of their transverse and tensile tests, 
taken with V2", i"-square and 1%" round bars. .. .460-467 
Summary of strength averages of round and square bars 

of about like areas. 469 

Rules for computing the relative strength of test bars, 

square and round . 476 

Transverse tests of bars cast flat and on end, showing 

the evils of casting flat, with analyses. 493, 494 

Tests and analyses of remelted furnace casts to test pig 

iron . 497 

Tests of chill roll iron, gun metal, car wheel iron, heavy 
machinery, stove plate and bessemer iron, with 
analyses, taken with \]/i', 1^4" and 1 15-16" round 

bars .536-537 

The A. F. A. transverse, tensile and compression, tests of 
bessemer, dynamo iron, light machinery, sand and 
chilled roll, sash weight, car wheel, stove plate, heavy 
machinery, cylinder iron, novelty iron, and gun iron, 

with analyses . 558-570 

Net weight of sand pig iron per ton of 2.268 pounds.. 589 
Net weight of chilled pig iron per ton of 2,240 pounds.. 590 

Chemical symbols and atomic weights . 591 

Value in degrees centigrade for each 100 degrees Fahr. . 591 
Heat of combustion, and scale of temper by color of iron 592 
Melting points of metal, relative conductivity of metals 
for heat and electricity, specific gravity and weight per 

• 

cubic inch of metals. 593 

Ultimate resistance to tension in pounds per square inch 
of different metals, strength of different woods and 
table of decimals equivalents of the fractional parts 
of an inch . 594 












INDEX. 


623 

Test Bars, Patterns, Moulding and Casting— PAGE. 

Design of and method for using fluidity strips to record 

the fluidity of metal .374, 502, 515-517, 519 

Design of pattern, flask and chills for moulding single 
round bars flat, but cast on end, with fluidity strips 

attached ..507-510 

Instructions for moulding and casting.508-510, 523-527 

Decimal equivalents for 1^5", i%" and 1 15-16" diame¬ 
ter ..510, 520 

Design of patterns, flasks and chill for moulding two 
round test bars flat, but cast on end, with fluidity 

strips and chill attached .512, 521, 522 

Designs for half circle chills and contraction tips for use 

in casting round test bars on end. 517 

Plan for obtaining contraction and making whirl gates.518-519 
Plans of patterns and moulding bars to be turned, either 

for transverse or tensile testing . 520 

Plans for moulding and casting plain bars on end. 

. 521-522, 527, 5/8-580 

General instructions on moulding, swabbing and pour¬ 
ing . 523 - 527 , 579-580 

Design of patterns, chill, fluidity strips and flasks used 

for the A. F. A. series of tests.542-544, 546, 548, 549 

The floor space and amount of labor required to mould 

one set of A. F. A. test bars.542, 550, 552 

Description of plan of moulding the A. F. A. test 
bars . 542 , 545 , 547 , 548-558 

Test Bars— 

Difference that variations in dampness of sand and pour¬ 
ing temperatures make in the strength and contraction 

of small H-inch bars. 453 , 457 , 484. 5 H, 525 

Unreliability of as small as Ui-inch square or round.... 

. 454-456, 467-468, 484, 511 

The size of test bars most suitable for testing different 

grades of iron .468-469, 477, 533, 535, 573 

Comments upon the difference in the uniformity of grain 

exhibited in round and square bars.469, 486, 576 

Formulas for computing the difference in area of test 



















INDEX. 


624 


PAGE. 


Test Bars— Continued. 

bars made off the same pattern and tested the same 

distance between supports .474, 476 

Necessity of records being taken, of the least difference 

in the area of bars made off the same pattern. 475 

Impracticability of formulas in vogue (to 1902) for com¬ 
puting the strength per square inch of cast iron in 

different cross sections and lengths .477, 53° 

Utility and necessity of using a micrometer to measure 

the area of .478-480 

The impracticability of casting two test bars of exactly 

the same area at the breaking point. 479 

Manner in which test bars should be placed for trans¬ 
verse testing .481-482 

Comparison of lines of crystallization in round and 

square .483-484 

Uneven cooling causing internal strains in . 485 

Examples of the uniformity of grains in round and non¬ 
uniformity in square.486-487 

Indorsement of the A. F. A. of round bars and recom¬ 
mendation of ik2-inch diameter as the smallest to be 

used .487, 573, 576, 577 

Deductions from tests showing the evils of casting bars 
flat and the difference in the results of such methods.. 489 
The importance of having uniform temperature of metal 

in pouring .526, 527, 540, 547, 580 

The utility of .528-531 

The different area and lengths of bars in use. 530 

The practicability of using bars 1 %" diameter and- 

larger .533, 573 

The necessity of using one size of bar in making com¬ 
parative tests of one or more grades of iron.533, 575 

The grade of iron that either one of three bars recom¬ 
mended by A. F. A. and the author are best suited 

f or .533, 577-579 

The first set of test bars made for the A. F. A. 541 

The character, size and number of test bars made for the 
A. F A.*.551, 553 



















INDEX. 


Test Bars— Continued. 


625 


PAGE. 


Making records of depressions at point of bearing in not¬ 
ing deflection of ...555, 576 

The adoption of the round bar for testing, by the A. F. 

A . 576 

Design and size of the A. F. A. bars, used for trans¬ 
verse and tensile tests .582, 583 


Testing Iron, General— 

The character of strains that cast iron is generally sub¬ 
jected to .220, 439 

Advisability of. taking drill tests and testing chilled 

castings .259, 432 

Effect of different temperatures in varying the depth of 

chilled iron .262, 372-374, 433 

Melting of brands, grades or mixtures in small cupolas 

for .267, 325, 362, 495-502 

Methods that are misleading in.277, 492, 576 

The best test for softness in light castings. 283 

Utility of transverse, crushing and impact tests.439-445, 448 

Methods for testing car wheels. 440 

Erratic and impractical records compiled previous to 

1895 . 449 , 539 

Evils of casting bars flat for.449, 488 

Analyses of the corner and middle body of square test 

bars . 451-453 

Comparative transverse, deflection and tensile tests of 
1 %" round bars in gun metal, chill roll, car wheel and 
four other specialties (analyses shown page 299).... 466 
Comparative tests showing that for the same area round 

bars record a greater strength than square ones. 469 

The first tests collected of different grades of iron.470 

Opportunities offered for deception or jugglery in testing 

bars cast flat . 492 

The cost of a set of appliances for casting and testing 
if/^-inch round bars. 


499 



















626 


INDEX. 


Testing Iron, General — page. 

Comparative transverse and deflection tests, with i l /&" 

1$/%" and i 15-16" bars, of chill roll, gun carriage, car 
wheel, heavy machinery, stove plate and bessemer 

iron, with analyses .535“537 

Conception of the plan to pour several tons of bars out 
of the same ladle and at the same temperature, as 

used by the A. F. A. in making 1601 tests. 540 

To whom credit is due for making the A. F. A. 

tests .540, 542, 555 

The difference in strength which the A. F. A. green sand 

and dry sand bars show. 557 

Comparative transverse, deflection, tensile and compres¬ 
sion tests from finished and rough bars, cast in green 
sand in 12 different grades or specialties of iron mix¬ 
tures as cast for A. F. A.558-570 

Compilation of the A. F. A. tests showing the transverse, 
tensile tests per square inch radicallv receding in oppo¬ 
site directions above an area of 1V2" diameter... .571-572 
Comments on the difference in strength of round and 


finished bars obtained by A. F. A.572-573 

Report of the A. F. A. committee recommending specifi¬ 
cations for tests of cast iron.574-584 

The inadvisability of taking coupons or tests from a 
casting as a guide to the casting’s strength. 576 

Tensile Tests— 


Strength of some especially strong iron mixtures. 

. 275, 276, 278, 300, 344 


The practicability of tensile tests. 449 

The relation tensile tests bear to transverse when kept 

under i^-inch diameter .450, 571 

Difficulties encountered in testing. 450 

Designs of bars for making turned bars for.458, 583 

Compilation of strength per square inch of rough and 
finished bars as obtained by A. F. A. 570 

Transverse Tests— 


The best for general use in testing cast iron. .. .220, 277, 439 

















INDEX. 


02 7 

Testing Machines — page. 

The necessity of and care in using. 481 

Advisability of a uniform speed in operating...481, 577 

Plan for delicately operating hand. 482 

Thermal Tests— 

The value of manganese to assist iron to withstand.... 271 
Methods of applying to car wheels.443, 444 

Titanium— 

Nature of its effects in iron.31, 218 








SOMETHING NEW. 

“Analyses of Pig Iron” 



From “ Iron and Steel ”— Chicago — Sept. S, ipoo. 


Volume One of “ Analyses of Pig Iron ” has just been issued 
by the compiler and publisher, Seymour R. Church, San Fran¬ 
cisco, Cal. As the first work of the kind ever published, it will 
interest every foundryman and user of pig iron. The substan¬ 
tial character of the work first attracts attention. It is a hand¬ 
some quarto volume, and its 172 pages, about 9x12 inches in 
size, are printed on heavy calendered paper and stoutly bound 
in heavy covers, fitted to endure long usage in the home of the 
iron maker. 

It is the contents, however, that are of the more lasting im¬ 
portance. There has been an increasing demand from foundry- 
men and others for analyses of different kinds of pig iron, and 
it was to meet this demand that the present work was issued. 
The correspondence involved in collecting these analyses com¬ 
prised several thousand letters, and if every furnace analysis is 
not presented it is because some makers of pig iron declined to 
furnish the desired information. The work has so grown upon 
the hands of the publisher that a supplementary volume, to 
contain entirely new matter and not a repetition of this initial 
volume, is already announced to appear early in the year 1901. 

A glance at the index shows the immense scope of the work. 
The names of more than 200 producing companies in the United 
States appear in the index and in the body of the work, and 
where analyses are not obtainable, that fact is stated. The 
index of brands analyzed also exceeds 200 names. 

The pig irons of foreign countries receive what seems ex¬ 
haustive treatment. Great Britain naturally takes the lead, 
and analyses appear of about 150 brands in England, besides a 
number in Scotland and Wales. The products of thirteen 
other nations, embracing all essential iron producers, receive 
adequate attention. 

The book is well illustrated. There appear many half-tone 
cuts, representing the fracture of different brands and grades 
of pig iron, showing the various characteristics of the iron. 
There are also a number of illustrations of furnace plants. 

Important and interesting statistics relative to the produc¬ 
tion of pig iron are included in this valuable work, w T hich will 
no doubt occupy a favorite niche in the office of the progressive 
pig iron melter. 


Volume II—now ready. It is not a repetition of Volume I, 
but contains new analyses and valuable articles on “ The Manu¬ 
facture and Use of Pig Iron.” 


Send in your order. Sold only by subscription 

Price, per volume, { ?," d s Clnad *- 


| Postage paid. 


Address: 


S. R. CHURCH, 307 Sansome Street, San Francisco, Cal., U. S. A. 





PRACTICAL WORKS BY A PRACTICAL MAN. 


Known worId=wide for their value. 

American Foundry Practice 

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In a review of the tenth edition of American Foundry 
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